Appendix G.5

Piedmont Lithium Carolinas,Inc. I Response to DEMLR Additional Information Request
Appendix G Response to DEMLR Mooresville Regional Office Comments
5. 1 Road, Parking, Walls, Fencing, and
Stream Crossing Construction Specifications

Piedmont Lithium Carolinas,Inc.I Response to DEMLR Additional Information Request ���
Attachment 5.1 —Road,Parking,Walls, Fencing,and Stream Crossing Specifications
Page No.
Table of Contents
Introduction ...................................................................................................................................2
Design Drawings, Plan View, Map, Construction Specifications and Cross Sections ..................2
Road Width, Gradient, and Surfacing Materials............................................................................2
Earthworkfor Roads.....................................................................................................................2
Culverts and Bridges for streams..................................................................................................3
Drainage Ditches, Drainage Structures & Erosion Control ...........................................................3
ParkingLots..................................................................................................................................3
SiteRetaining Walls......................................................................................................................3
Fencing/Gates/Guardrail...............................................................................................................4
Operation and Maintenance Procedures ......................................................................................4
Certification and Periodic Inspection Procedures .........................................................................4
Abandonment and/or Removal Plan.............................................................................................4
1

Piedmont Lithium Carolinas,Inc.I Response to DEMLR Additional Information Request ���
Attachment 5.1 —Road,Parking,Walls, Fencing,and Stream Crossing Specifications
Introduction
The Lithium Hydroxide Conversion Plant will include site plan elements such as an access road,
parking lots, fencing and walls. The Lithium Hydroxide Conversion Plant general specifications
are noted here.
Design Drawings, Plan View, Map, Construction
Specifications and Cross Sections
See design drawings for a site plan of the Lithium Hydroxide Conversion Plant.
• Clearing and Grubbing — Clearing and grubbing shall be done as described in this
application.
• Excavation — Site Excavation is described in Appendix G, Attachment 5.3.
• Culverts — Major stream crossings shall be installed at the approximate locations shown
on the design drawings. Size requirements are included in this section. Site storm
drainage is described in Appendix G, Attachment 5.3.
Road Width, Gradient, and Surfacing Materials
Road widths shall be as shown in the design drawings for the access drive, site loop and
maintenance drives around and along the rail. Subgrade, base courses and surfacing materials
shall be as shown in the design drawings and shall be installed per the North Carolina
Department of Transportation's Standard Specifications for Roads and Structures 2018 addition
and any additions. Standard Specifications Library - All Documents (ncdot.gov). All roads should
be constructed to provide positive drainage off the drivable surface to roadside ditches and/or
drainage structures. Road gradients can be determined from the design drawings but will have a
maximum slope of 5%. Road cross-slopes shall be 2% minimum and 3% maximum.
Earthwork for Roads
Roads for the Lithium Hydroxide Conversion Plant are internal drives and thus the
earthwork/grading associated with them fall within the same earthwork for other site elements
including the facility pad and associated parking. Earthwork specifications can be found in
Appendix G, Attachment 5.3.
2

Piedmont Lithium Carolinas,Inc.I Response to DEMLR Additional Information Request ���
Attachment 5.1 —Road,Parking,Walls, Fencing,and Stream Crossing Specifications
Arch Spans and Bridges for Streams
Arch spans or bridges associated with the crossing of streams on the conversion plant site shall
be installed beneath roadways at the approximate locations as shown on the drawings. Where
applicable, arch spans and bridges may need to follow the North Carolina Department of
Transportation's Standard Specifications for Roads and Structures 2018 addition (and any
additions) or the manufacturer's recommendations and specifications if a proprietary system
(e.g. structural plate bottomless arch culvert). Sizing of the crossings shall be found in the
design drawings.
Drainage Ditches, Drainage Structures & Erosion
Control
See Appendix G, Attachment 5.3 for drainage and erosion control specifications including
maintenance.
Parking Lots
Parking lots are provided for in various locations as shown in the design drawings. Subgrade,
base courses and surfacing materials shall be as shown in the design drawings and shall be
installed per the North Carolina Department of Transportation's Standard Specifications for
Roads and Structures 2018 addition and any additions. Standard Specifications Library - All
Documents (ncdot.gov). All parking lots should be constructed to provide positive drainage off
the drivable surface to ditches and/or drainage structures. Parking lot gradients can be
determined from the design drawings but will have a maximum slope of 4% and a minimum
slope of 2%. Depending on use, parking lots may be a mix of heavy duty and light duty
pavement. Striping of parking lots shall be with thermoplastic paint. Accessible parking spaces
shall not exceed a slope of 2% in any direction.
Site Retaining Walls
Site retaining walls shall be installed where indicated within the design drawings and in the
manner to be described within detailed structural drawings (e.g. cast-in-place, segmental block,
etc.). Additional specifications may be required from a manufacturer in the use of a segmental
block wall or similar.
3

Piedmont Lithium Carolinas,Inc.I Response to DEMLR Additional Information Request ���
Attachment 5.1 —Road,Parking,Walls, Fencing,and Stream Crossing Specifications
Fencing/Gates/Guardrail
Various fencing will be used on the site including perimeter security fencing§, various gates
(vehicular and pedestrian) and along the top of walls to provide safety barriers. Unless special
provisions/specifications are provided by a manufacturer, fencing, gates and guardrails shall be
installed per the North Carolina Department of Transportation's Standard Specifications for
Roads and Structures 2018 addition and any additions.
Operation and Maintenance Procedures
Operation and maintenance procedures will consist of keeping a durable surface and keeping
sediment and drainage control structures maintained and operational. A road, wall, fencing,
gates, etc. damaged by a catastrophic event will be repaired as soon as practical after the
damage has occurred. Culverts shall be kept free of accumulating debris and shall be inspected
after heavy rainfall events.
Certification and Periodic Inspection Procedures
Access roads shall be inspected as part of the weekly site inspections required for the facility.
Certification of road construction shall be included in the required quarterly and annual reports.
Abandonment and/or Removal Plan
Buildings and equipment will be deconstructed after they are no longer needed for production
operations. Roads and rail will remain on the site for future industrial use. Regrading of slopes
shall be performed as necessary to be compatible with the post-mining land use and
revegetation requirements, and to compliment the natural drainage pattern of the surrounding
terrain.
4

Piedmont Lithium Carolinas,Inc. I Response to DEMLR Additional Information Request
Appendix G Response to DEMLR Mooresville Regional Office Comments
5.2 Rail Construction Specifications

Piedmont Lithium Carolinas,Inc.I Response to DEMLR Additional Informaiton Request ���
Attachment 5.2—Rail Construction Specifications
Page No.
Table of Contents
Introduction ...................................................................................................................................1
Design Drawings, Plan View, Map, Construction Specifications and Cross Sections ..................1
Culverts, Bridges, and Low-Water Crossings ...............................................................................1
Drainage Ditches and Structures..................................................................................................1
Operation and Maintenance Procedures ......................................................................................1
Certifications and Periodic Inspection Procedures .......................................................................2
ReclamationPlan..........................................................................................................................2
TrackDesign.................................................................................................................................2

Piedmont Lithium Carolinas,Inc.i Response to DEMLR Additional Informaiton Request ���
Attachment 5.2—Rail Construction Specifications
Introduction
Rail access is provided to the site with a connection to the existing CSX main track. The lead
track crosses Hephzibah Church Road and extends through the site to the Lithium Hydroxide
Conversion Plant. Ditches, sediment traps, culverts, and silt fence will control the runoff from
the rail, storage yard, and associated access roads.
Design Drawings, Plan View, Map, Construction
Specifications and Cross Sections
A plan view of the rail and access road is shown on the Overall Site Plan Map (Appendix G,
Attachment 1), and profiles are included in Appendix G, Attachment 4.
• Clearing and Grubbing — Clearing and grubbing shall be done as described in this
application.
• Excavation — If excavation is required to construct the rail and yard area, excavations
shall not be steeper than 2H:1 V (Horizontal:Vertical) in soil or 0.25H:1 V in rock. Details
regarding road construction are provided in this section.
• Culverts — Culverts shall be installed at the approximate locations shown on the design
drawings. Size requirements are included in this section.
Culverts, Bridges, and Low-Water Crossings
Ditch culverts shall be installed beneath the rail at the approximate locations as shown on the
drawings.
Drainage Ditches and Structures
The appropriate road ditches and sediment traps will be installed at the approximate locations
as shown on the drawings.
Operation and Maintenance Procedures
Operation and maintenance procedures will consist of keeping a durable surface and keeping
sediment and drainage control structures maintained and operational. A rail structure damaged
by a catastrophic event will be repaired as soon as practical after the damage has occurred.
1

Piedmont Lithium Carolinas,Inc.I Response to DEMLR Additional Informaiton Request ���
Attachment 5.2—Rail Construction Specifications
Certifications and Periodic Inspection Procedures
Rail lines and storage yards shall be inspected as part of the weekly site inspections required
for the facility. Certification of rail construction shall be included in the required quarterly and
annual reports.
Reclamation Plan
Rail and associated access roads will remain in place for future industrial site use.
Track Design
Rail access is provided to the site with a connection to the existing CSXT main track with a No.
10 right hand turnout. The lead track crosses Hephzibah Church Road at-grade and extends
through the site to the processing plant. The storage yard connects to the lead track
approximately 600 feet from the Hephzibah Church Road grade crossing. The maximum
horizontal curve is 12 degrees and the maximum compensated track grade is 2.50%. The
grade across the stream leading up to and through the plant site is 0.00%. The grade through
the storage tracks is 0.00%. A 15-foot-wide access road is provided adjacent to the lead track
and around the perimeter of the storage yard. The storage yard consists of seven tracks with
capacity for 54 rail cars. The fill slopes off the lead track are a maximum of 2:1. The fill slopes
off the storage tracks is 3:1 typical, 2:1 maximum. All track construction shall be in accordance
with the CSX Standard Specifications for the Design and Construction of Private Sidetracks.
2

Piedmont Lithium Carolinas,Inc. I Response to DEMLR Additional Information Request
Appendix G Response to DEMLR Mooresville Regional Office Comments
5.3 Drainage and Sediment Structure
Specifications

Piedmont Lithium Carolinas,Inc.i Response to DEMLR Additional Information Request ���
Attachment 5.3—Drainage and Sediment Structure Specifications
Page No.
Table of Contents
SitePreparation ............................................................................................................................2
Demolition.....................................................................................................................................2
SiteGrading/Excavation ...............................................................................................................2
ErosionControl Measures ............................................................................................................2
Sediment Control Structural BMP Excavation ..............................................................................3
Stockpiles......................................................................................................................................3
DitchLining —Vegetated...............................................................................................................3
Ditch Lining — Erosion Control Blanket .........................................................................................3
DitchLining — Rock Riprap ...........................................................................................................4
Ditch Lining — Grouted Rock Riprap .............................................................................................4
WorkingEdge Ditches ..................................................................................................................4
DitchMaintenance ........................................................................................................................4
DitchOutlets .................................................................................................................................5
Culverts and Storm Drainage........................................................................................................5
Culvert/Storm Drainage Riprap Outlet Protection.........................................................................5
CleaningUp ..................................................................................................................................5
Restoration of Surface and/or Structures......................................................................................5
Maintenance — Erosion and Sediment Control .............................................................................5
Maintenance — Storm Drainage ....................................................................................................6
1

Piedmont Lithium Carolinas,Inc.I Response to DEMLR Additional Information Request ���
Attachment 5.3—Drainage and Sediment Structure Specifications
Site Preparation
All obstructions and vegetative material will be removed with the boundaries of the limits of
disturbance as is necessary for the construction of rail corridor, entrance drives, facility site,
parking, sediment control Best Management Practices (BMPs) and other project infrastructure.
Demolition
All demolition material shall be disposed of off-site in a legal manner, unless noted otherwise.
Site Grading/Excavation
Site Grading will conform to the lines, grades, and cross-sections shown on the applicable
design drawings located in Appendix G, Attachment 4. Excavated slopes shall meet the percent
grade established within the drawings and at no time shall be steeper than 2:1. Fill areas shall
be compacted under the direction of a geotechnical engineer using material that is suitable for
structural fill and placed in lifts of a thickness that specified density can readily be achieved.
Compaction requirements shall be a minimum of:
Under Paved Areas, Sidewalks and Piping: Minimum 95% per ASTM D698 for Cohesive Soils.
Unpaved Areas: 90% per ASTM D698 for Cohesive Soils.
Inside of structures under foundations, under equipment support pads, under slabs-on-grade
and scarified existing subgrade under fill material: 98% per ASTM D698 and 100% in the top 12
inches for Cohesive Soils.
Outside structures next to walls, piers, columns, and any other structure exterior member: 92%
per ASTM D698 for Cohesive Soils.
Erosion Control Measures
The following additional erosion and sediment control measures, if required and shown within
the design drawings shall be constructed and maintained per the North Carolina Erosion and
Sediment Control Planning and Design Manual. Where applicable, install per the manufacturer's
recommendations and specifications:
• Tree protection fencing
• Silt Fence (including J-Hooks)
• Inlet Protection
• Slope Drains
2

Piedmont Lithium Carolinas,Inc.I Response to DEMLR Additional Information Request ���
Attachment 5.3—Drainage and Sediment Structure Specifications
• Rock Check Dams and/or Sediment Tubes
• Slope Matting
• Dust Control
• Construction Entrance
• Culvert Inlet Protection
• Temporary Diversions
• Temporary/Permanent Seeding
• Concrete Washout
• Sediment Basins
• Sediment Traps
Sediment Control Structural BMP Excavation
The completed sediment basins and sediment traps will conform to the cross-sections and
design information shown on the applicable design drawings located in Appendix G, Attachment
4. Structural Sediment Control BMPs shall be developed and constructed in accordance with
the North Carolina Erosion and Sediment Control Planning and Design Manual: NC DEQ:
Erosion and Sediment Control Planning and Design Manual. Prior to installation of the BMPs
the site shall be cleared and grubbed of all organic and unsuitable material. Topsoil material
shall be removed and stockpiled. All obstructions will be removed along the line as is necessary
for the construction of the BMP features.
Stockpiles
Incorporate stockpiles near the area of work. Protect all stockpiles with erosion control
measures, but at a minimum include silt fence on the downstream side. Stockpiles shall be
stabilized or covered when not in use.
Ditch Lining — Vegetated
Vegetated lining, when required, will be placed upon completion of final grade of ditch line, the
ditch shall be vegetated according to the vegetation plan. Channels requiring vegetated lining
shall be covered with a layer of soil having a minimum thickness of 12 inches.
Ditch Lining — Erosion Control Blanket
Erosion Control Blanket Lining, when required for ditch stabilization, will be placed upon
completion of final grade of ditch line and installed per the manufacturer's recommendations
3

Piedmont Lithium Carolinas,Inc.I Response to DEMLR Additional Information Request ���
Attachment 5.3—Drainage and Sediment Structure Specifications
and specifications. Blanket design strength will be as noted in the design drawings. The ditch
shall be vegetated according to the vegetation plan.
Ditch Lining — Rock Riprap
Rock riprap lining, when required, will be placed in an eighteen (18) inch minimum thick blanket
on the bottom and sides of the channel. The rock will be non-toxic, non-acid producing, durable
rock having a minimum slake durability of ninety-five (95) percent and a median diameter (d50)
of twelve inches (12"). Twenty-five (25) percent by weight of the rock will be one and one-half
(1-1/2) times the median diameter or slightly larger. The remaining seventy-five (75) percent will
be well-graded material consisting of sufficient rock small enough to fill the voids between the
larger rocks.
Ditch Lining — Grouted Rock Riprap
Grouted rock riprap lining, when required, will be placed in an eighteen (18) inch thick blanket
on the bottom and sides of the channel. The rock will be non-toxic, non-acid producing, durable
rock having a minimum slake durability of ninety-five (95) percent. The sizing of the rock shall
range in nominal diameter from three (3) inches to eighteen (18) inches with a minimum median
diameter (d50) of twelve (12) inches. Twenty-five (25) percent by weight of the rock will be one
and one half(1 — 1/2) times median diameter or slightly larger. Ten (10) percent of the rock
shall be no smaller than three (3) inches. The remaining sixty-five (65) percent of the rock will
be graded between three (3) and eighteen (18) inches. The grout shall be a sand/cement
mixture with enough water added to yield a workable consistency that will fully penetrate the
rock riprap. The grout mixture shall develop a twenty-eight (28) day compressive strength of
three thousand (3000) psi. The grout mixture shall be approved by the Engineer and/or Owner
prior to placement.
Working Edge Ditches
Working edge ditches, when required, will be constructed in natural ground or compacted fill
and maintained as necessary to control surface drainage.
Ditch Maintenance
The ditches will be kept free of sediment and other debris during the working life of the facility so
that the flow of water will remain unimpeded. If needed, critical sections will be covered with
rock.
4

Piedmont Lithium Carolinas,Inc.I Response to DEMLR Additional Information Request ���
Attachment 5.3—Drainage and Sediment Structure Specifications
Ditch Outlets
The ditches will outlet as shown on the plans. The outlet area will be riprapped if necessary and
disturbed soil areas will be revegetated according to the vegetation plan.
Culverts and Storm Drainage
Site Culverts and storm drainage shall be constructed per the details and to the grade lines
shown in the design drawings. All storm material and construction practices including but not
limited to piping, structures, bedding, compaction, dewatering, etc. shall be per the North
Carolina Department of Transportation's Standard Specifications for Roads and Structures 2018
addition and any additions. Standard Specifications Library -All Documents (ncdot.gov). Note:
see Appendix G, Attachment 5.1 for arch spans and bridges associated with stream crossings.
Culvert/Storm Drainage Riprap Outlet Protection
The outlet area for site storm drainage will be riprapped per the dimensions and class of riprap
found within the design drawings and placed on a layer of nonwoven geotextile fabric.
Cleaning Up
Surplus material, tools and temporary structures will be removed by the Contractor. All dirt,
rubbish and excess earth from the excavation will be hauled to an approved disposal area
provided by the Contractor and the construction site will be left clean to the satisfaction of the
Engineer and/or Owner.
Restoration of Surface and/or Structures
The contractor will restore the surface and/or structures disturbed to a condition equal to that
before the work began and to the satisfaction of the Engineer and/or Owner and will furnish all
labor and material incidental thereto. All graded areas shall receive stabilization in the form of
permanent lawn via seeding. Reference the seeding specifications within the design drawings.
Maintenance — Erosion and Sediment Control
Reference the North Carolina Erosion and Sediment Control Planning and Design Manual for
detailed maintenance guidelines for each erosion and sediment control best management
5

Piedmont Lithium Carolinas,Inc. I Response to DEMLR Additional Information Request
Attachment 5.3—Drainage and Sediment Structure Specifications
practice (BMP) used within the project. In general, inspect all BMPs weekly and after each
rainfall event. Remove accumulated sediment where applicable and dispose of off-site or in a
protected stockpile onsite. Keep all stone clean where applicable for a specific measure.
Concrete Washout must maintain adequate holding capacity plus a freeboard of 12 inches.
Remove any trash/debris found within the BMPs. Immediately repair any damaged BMP.
Replace BMPs that continue to fail with a more structural BMP if stabilization can't be met.
Maintenance — Storm Drainage
Remove any accumulated trash and debris. Flush system at end of construction. Remove any
grout/concrete deposits in pipes and structures immediately so as not to impede the system
hydraulics.
6

Piedmont Lithium Carolinas,Inc. I Response to DEMLR Additional Information Request
Appendix G Response to DEMLR Mooresville Regional Office Comments
5.4 Conversion Plant Drainage Calculations

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PLC I Lithium Hydroxide Conversion Plant—Stormwater Calculations
Contents
Contents
Contents .................................................................................................................................... 1
1.0 Project Description .......................................................................................................... 2
2.0 Site Information ............................................................................................................... 2
2.1 Project Location........................................................................................................... 2
2.2 Soils............................................................................................................................. 2
2.3 Topography.................................................................................................................. 2
2.4 Site Characteristics...................................................................................................... 2
3.0 Erosion Control Calculations ........................................................................................... 3
3.1 Sediment Basins.......................................................................................................... 3
3.2 Sediment Traps ........................................................................................................... 3
4.0 Stormwater Calculations.................................................................................................. 3
5.0 Culvert and Stream Crossing Calculations ...................................................................... 4
Appendices
Appendix A— FEMA Firmette Map
Appendix B — USGS Topo Map
Appendix C — Drainage Area Maps
Appendix D — Soil Map and Report
Appendix E — Curve Number and Time of Concentration
Appendix F — NOAA Rainfall Data
Appendix G — Sediment Basin Calculations
Appendix H — Sediment Trap Calculations
Appendix I —Stormwater Calculations
Appendix J — Stream and Culvert Crossing Calculations
Appendix K— Outlet Protection Calculations
1

PLC I Lithium Hydroxide Conversion Plant—Stormwater Calculations ���
Project Description
1 .0 Project Description
Piedmont Lithium Carolinas, Inc. is proposing an integrated facility in Gaston County, North
Carolina that will include both Concentrate Operations (including Mine#1, Concentrate Plant, and
Industrial Minerals Plant)as well as a Lithium Hydroxide Conversion Plant. HDR Engineering, Inc.
(HDR) is providing site layout, grading, stormwater, and erosion control plans for the Lithium
Hydroxide Conversion Plant. This will include an entrance road, rail access, rail storage, the plant
and associated administrative, operations, and maintenance buildings. This report will address
the site stormwater analysis and design.
2.0 Site Information
2.1 Project Location
The Lithium Hydroxide Conversion Plant will be located east of Cherryville on a combined
parcel of property just south of Hephzibah Church Road. The property is bound on the west by
Anthony Grove Road, and on the east by Saint Marks Church Road.
2.2 Soils
The onsite soils consist of both sandy and clay loams, (see soils map in Appendix D) with
moderate to poor infiltration rates. The majority of the site soils have a hydrologic soil group
rating `B', with a small percentage of'D' or 'B/D' ratings.
2.3 Topography
Elevations range from 910 feet NAVD at the corner of Anthony Grove Road and Hephzibah
Church Road to 795 feet NAVD where Beaverdam Creek crosses St. Marks Church Road. The
existing topography is shown on the Drainage Area Maps in Appendix C of this report.
2.4 Site Characteristics
This site is located within a Water Supply— IV (WS-IV) watershed protected area. The site will
be developed under the low density option with less than 24% built upon area and 30-foot
stream buffers, following the standard rules for erosion and sediment controls, as set forth by
the North Carolina Department of Environmental Quality (NCDEQ).
2

PLC I Lithium Hydroxide Conversion Plant—Stormwater Calculations ���
Erosion Control Calculations
3.0 Erosion Control Calculations
3.1 Sediment Basins
All sediment basins are designed per NCDEQ standards. They are designed for a 25-year
design storm, using local rainfall data (see Appendix F). Basins have a minimum surface area
ratio of 435 ft2/cfs or greater, with appropriate length-to-width ratios and inflow points located as
far as possible from the principal spillway inlet. All basins exceed the minimum volume
requirement of 1,800 ft3/acre. Basins are to be constructed with a primary spillway and
skimmer, as well as an emergency spillway designed to maintain 1-foot of freeboard. Porous
baffles are to be installed to reduce velocity and turbulence of the water flowing through the
basin.
3.2 Sediment Traps
For drainage areas less than 5 acres, sediment traps have been designed per NCDEQ
standards with a 25-year design storm based on local rainfall data. Each trap has a minimum
surface area ratio of 435 ft2/cfs or greater and meet the minimum volume requirement of 3,600
ft3/acre of disturbed area. All sediment traps are to be constructed per NCDEQ minimum design
criteria with a modified spillway designed to detain flow and allow improved sediment trapping
(see plan sheet 17 of 20 for details).
4.0 Stormwater Calculations
Storm sewer piping will convey stormwater runoff from the roadside ditches surrounding
conversion plant to the sediment basins. Using HydroCAD version 10.10-5a analysis software,
the storm sewer was designed based on the 25-year storm, as developed from local rainfall
data. The storm sewer sizes were designed for full development, using a minimum time of
concentration of 6 minutes. All proposed storm sewer pipes were designed assuming a
minimum slope of 1% and a roughness coefficient of n= 0.012. The roadside ditches
surrounding the conversion plant were also designed based on the 25-year storm and local
rainfall data. The ditches are designed at a minimum slope of 1% with a 1-foot flat bottom and
3:1 side slopes assuming a roughness coefficient of n= 0.025. (see Appendix 1).
3

PLC I Lithium Hydroxide Conversion Plant—Stormwater Calculations ���
Culvert and Stream Crossing Calculations
5.0 Culvert and Stream Crossing Calculations
To provide access to the site, an entrance road must be constructed from Hephzibah Church
Road to the plant and will include 3 different culvert crossings along the route. The 3 crossings
are designed for the 25-year design storm and checked for the 100 year storm to prevent
overtopping using local rainfall data (see Appendix F). The first culvert crossing will consist of a
24-inch culvert with a contributing drainage area of 2.50 acres. The second crossing was sized
as 36-inch culvert for the 5.59 acres of contributing drainage area. The last culvert along the
entrance road, with a 74.73-acre drainage area, was sized to be an open bottom metal arch
span of 10 ft. with a rise of 5.25-ft. The open bottom arch will allow the delineated stream to be
unimpacted in the area. (see Appendix J).
A railroad system is also shown to the south of the main entrance road. It will provide service
from the main CSX line, north of Hephzibah Church Road, to the plant site. The railroad will
require 2 drainage crossings: a culvert crossing near Hephzibah Church Road and a crossing
along the delineated stream. The culvert crossing will be a 48-inch culvert with a contributing
drainage area of 14.22 acres. The stream crossing has a contributing drainage area of 149.8
acres. An open bottom arch span of 14-feet with a rise of 7.25-feet was sized to accommodate
the crossing and to prevent the stream from being impacted. (see Appendix J).
The hydrographs for each culvert were created using Hydraflow Extensions for Civil 3D 2018
(see Appendix J). The curve numbers and time of concentrations are showing in Appendix E for
they hydrograph calculations. The culvert crossing design and analysis were performed using
HY8 version 7.60 by FHA (see Appendix J).
4

PLC I Lithium Hydroxide Conversion Plant ���
Appendices
AppendixA — FEMA Firmette
Map

National Flood Hazard Layer FIRMette FEMA Legend
81°19'48"W 35o24'3"N SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT
f
yl Without Base Flood Elevation(BFE)
Zone A,V,A99
w Iww% t SPECIAL FLOOD With BFE or Depth Zone Ae,AO,AH,VE,AR
_ lei r HAZARD AREAS Regulatory Floodway
+ ICI s 0.2%Annual Chance Flood Hazard,Areas
- of 1%annual chance flood with average
I�it # * depth less than one foot or with drainage
f * ', ` f, I # r {i areas of less than one square mile zone x
*!r FFuture Chance
Flood
l%Annual
_ Chance Flood Hazard zone
Area with Reduced Flood Risk due to
- •t OTHER AREAS OF Levee.See Notes.zone x
} # FLOOD HAZARD Area with Flood Risk due to Leveezone D
NO SCREEN Area of Minimal Flood Hazard zonex
' Q Effective LOMRs
# OTHER AREAS Area of Undetermined Flood Hazard zone
GENERAL ---- Channel,Culvert,or Storm Sewer
STRUCTURES IIIIIII Levee,Dike,or Floodwall
Cross
AREA OF IVIINI VIAL FLOOD I-IP I RD � Water Surface
Elevation
1%Annual Chance
i 17•5 Water Surface Elevation
Z?O 8- - - Coastal Transect
b _ ^^^^ 513— Base Flood Elevation Line(BFE)
•- LTA
" + tr L }+ Limit of Study
Jurisdiction Boundary
370455 —--- Coastal Transect Baseline
OTHER _ Profile Baseline
FEATURES Hydrographic Feature
w
Digital Data Available N
dIP + 4
No Digital Data Available
+y
} Awl' . _ . t MAP PANELS Unmapped
iF F •di. q Q
rt '; The pin displayed on the map is an approximate
+ point selected by the user and does not represent
■ an authoritative property location.
This map complies with FEMA's standards for the use of
w _ digital flood maps if it is not void as described below.
The basemap shown complies with FEMA's basemap
accuracy standards
The flood hazard information is derived directly from the
# authoritative NFHL web services provided by FEMA.This map
was exported on 8/26/2021 at 5:09 PM and does not
r A Y• reflect changes or amendments subsequent to this date and
.. • I qp time.The NFHL and effective information may change or
y Z on 2 E become superseded by new data over time.
This map image is void if the one or more of the following map
elements do not appear:basemap imagery,flood zone labels,
legend,scale bar,map creation date,community identifiers,
EKZZZM 81019'11"W 35023'34"N FIRM panel number,and FIRM effective date.Map images for
Feet 1:6 000 unmapped and unmodernized areas cannot be used for
0 250 500 1,000 1,500 2,000 regulatory purposes.
Basemap:USGS National Map:Orthoimagery.Data refreshed October,2020

PLC Lithium Hydroxide Conversion Plant ���
Appendices
Appendix B — USGS Topo
Map

U
��� U.S. DEPARTMENT OF THE INTERIOR The National Map LINCOLNTON WEST QUADRANGLE
U. S. GEOLOGICAL SURVEY I '� �O�O NORTH CAROLINA
science for a changing world U 7.5-MINUTE SERIES
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81°22'30" 67 68 69 20' 70 71 72 73 17,30„ 74 75 76 77 E81°15'
Produced by the United States Geological Survey * SCALE 1:24 000 ROAD CLASSIFICATION
North American Datum of 1983(NAD83)
World Geodetic System of 1984(WGS84). Projection and N. 1 0.5 0 KILOMETERS 1 2 NORTH Expressway o Local Connector
1 000-meter grid:Universal Transverse Mercator,Zone 17S 7' 14' ■CAROLINA Secondary Hwy Local Road
10 000-foot ticks:North Carolina Coordinate System of 1983 128 MILS 1000 500 0 METERS 1000 2000
01 11' 1 0.5 0 1 Ramp 4WD
3 MILS MILES .Interstate Route 0 US Route O State Route
1000 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 QUADRANGLE LOCATION
Imagery..................................................NAIP,June 2012 UTM GRID AND 2013 MAGNETIC NORTH FEETDECLINATION AT CENTER OF SHEET
Roads..............................................©2006-2012 TomTom Banoak Reepsville Maiden
Names..........................................................GNIS, 2013 U.S.National Grid CONTOUR INTERVAL 20 FEET
Hydrography....................National Hydrography Dataset,2012 100,000-m Square ID NORTH AMERICAN VERTICAL DATUM OF 1988
Contours............................National Elevation Dataset, 2008
Boundaries....................Census, IBWC, IBC,USGS, 1972-2012 y Lineolnton Lineolnton
My This map was produced to conform with the Cherrville West East
National Geospatial Program US Topo Product Standard,2011.
A metadata file associated with this product is draft version 0.6.11 LINCOLNTON WEST, NC
Grid Zone Designation
17S Waco Bessemer Gastonia
City North 2013
ADJOINING 7.5'QUADRANGLES

PLC Lithium Hydroxide Conversion Plant ���
Appendices
Appendix C — Drainage Area
Maps

"N
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LITHIUM HYDROXIDE CONVERSION PLANT

PLC Lithium Hydroxide Conversion Plant ���
Appendices
Appendix D — Soil Map and
Report

3 Hydrologic Soil Group—Gaston County, North Carolina
N M
O W
N
W W
469700 470000 470300 470600 470900 471200 471500 471800
35'24'30"N 35'24'30"N
00
wr e
R3 &npV
o
� o
• es
D
D �(
°
JJ `F l
• D
D
o
D
-4 4
35'22'57"N 35'22'57'N
469700 470000 470300 470600 470900 471200 471500 471800
3 3
N i0
Map Scale:1:14,000 if printed on A portrait(8.5"x 11")sheet.
o
N Meters
0 200 400 800 1200
Feet
0 500 1000 2000 3000
Map projection:Web Mercator Comer coordinates:WGS84 Edge tics:L TM Zone 17N WGS84
UsDA Natural Resources Web Soil Survey 8/26/2021
Conservation Service National Cooperative Soil Survey Page 1 of 5

Hydrologic Soil Group—Gaston County, North Carolina
MAP LEGEND MAP INFORMATION
Area of Interest(AOI) p C The soil surveys that comprise your AOI were mapped at
Area of Interest(A01) 0 C/D 1:24,000.
Soils Please rely on the bar scale on each map sheet for map
Soil Rating Polygons 0 D measurements.
0 A p Not rated or not available Source of Map: Natural Resources Conservation Service
0 A/D Water Features Web Soil Survey URL:
Streams and Canals Coordinate System: Web Mercator(EPSG:3857)
0 B Transportation Maps from the Web Soil Survey are based on the Web Mercator
0 B/D projection,which preserves direction and shape but distorts
Rails distance and area.A projection that preserves area,such as the
0 C #%-0 Interstate Highways Albers equal-area conic projection,should be used if more
accurate calculations of distance or area are required.
C/D US Routes
0
This product is generated from the USDA-NRCS certified data as p Major Roads of the version date(s)listed below.
Not rated or not available Local Roads
Soil Survey Area: Gaston County,North Carolina
Soil Rating Lines Background Survey Area Data: Version 20,Jun 4,2020
" x A ® Aerial Photography Soil map units are labeled(as space allows)for map scales
" r A/D 1:50,000 or larger.
B Date(s)aerial images were photographed: Apr 23,2014—Nov
B/D 28,2017
The orthophoto or other base map on which the soil lines were
" x C compiled and digitized probably differs from the background
" 0 C/D imagery displayed on these maps.As a result,some minor
shifting of map unit boundaries may be evident.
" r D
" r Not rated or not available
Soil Rating Points
0 A
0 A/D
B
B/D
UU� Natural Resources Web Soil Survey 8/26/2021
� Conservation Service National Cooperative Soil Survey Page 2 of 5

Hydrologic Soil Group—Gaston County, North Carolina
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
ApB Appling sandy loam, 1 to B 181.2 28.5%
6 percent slopes
CeB2 Cecil sandy clay loam,2 B 87.3 13.7%
to 8 percent slopes,
moderately eroded
CeD2 Cecil sandy clay loam,8 B 53.9 8.5%
to 15 percent slopes,
moderately eroded
CfB Cecil-Urban land B 7.5 1.2%
complex,2 to 8
percent slopes
ChA Chewacla loam,0 to 2 B/D 50.6 7.9%
percent slopes,
frequently flooded
HeB Helena sandy loam, 1 to D 14.5 2.3%
6 percent slopes
LdB2 Lloyd sandy clay loam,2 B 53.0 8.3%
to 8 percent slopes,
moderately eroded
MaB2 Madison sandy clay B 0.7 0.1%
loam,2 to 8 percent
slopes,moderately
eroded
MaD2 Madison sandy clay B 0.1 0.0%
loam,8 to 15 percent
slopes,moderately
eroded
PaD2 Pacolet sandy clay B 9.1 1.4%
loam,8 to 15 percent
slopes,moderately
eroded
PaE Pacolet sandy loam, 15 B 71.8 11.3%
to 25 percent slopes
W Water 2.2 0.3%
WeD Wedowee sandy loam,6 B 98.3 15.4%
to 15 percent slopes
WoA Worsham loam,0 to 2 D 6.3 1.0%
percent slopes
Totals for Area of Interest 636.4 100.0%
USDA Natural Resources Web Soil Survey 8/26/2021
Conservation Service National Cooperative Soil Survey Page 3 of 5

Hydrologic Soil Group—Gaston County, North Carolina
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential)when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential)when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
usDA Natural Resources Web Soil Survey 8/26/2021
Conservation Service National Cooperative Soil Survey Page 4 of 5

Hydrologic Soil Group—Gaston County, North Carolina
Aggregation is the process by which a set of component attribute values is
reduced to a single value that represents the map unit as a whole.
A map unit is typically composed of one or more "components". A component is
either some type of soil or some nonsoil entity, e.g., rock outcrop. For the
attribute being aggregated, the first step of the aggregation process is to derive
one attribute value for each of a map unit's components. From this set of
component attributes, the next step of the aggregation process derives a single
value that represents the map unit as a whole. Once a single value for each map
unit is derived, a thematic map for soil map units can be rendered. Aggregation
must be done because, on any soil map, map units are delineated but
components are not.
For each of a map unit's components, a corresponding percent composition is
recorded. A percent composition of 60 indicates that the corresponding
component typically makes up approximately 60% of the map unit. Percent
composition is a critical factor in some, but not all, aggregation methods.
The aggregation method "Dominant Condition"first groups like attribute values
for the components in a map unit. For each group, percent composition is set to
the sum of the percent composition of all components participating in that group.
These groups now represent"conditions" rather than components. The attribute
value associated with the group with the highest cumulative percent composition
is returned. If more than one group shares the highest cumulative percent
composition, the corresponding "tie-break" rule determines which value should
be returned. The "tie-break" rule indicates whether the lower or higher group
value should be returned in the case of a percent composition tie. The result
returned by this aggregation method represents the dominant condition
throughout the map unit only when no tie has occurred.
Component Percent Cutoff. None Specified
Components whose percent composition is below the cutoff value will not be
considered. If no cutoff value is specified, all components in the database will be
considered. The data for some contrasting soils of minor extent may not be in the
database, and therefore are not considered.
Tie-break Rule: Higher
The tie-break rule indicates which value should be selected from a set of multiple
candidate values, or which value should be selected in the event of a percent
composition tie.
usDA Natural Resources Web Soil Survey 8/26/2021
Conservation Service National Cooperative Soil Survey Page 5 of 5

PLC Lithium Hydroxide Conversion Plant
Appendices
Appendix E — Curve Number
and Time of Concentration

Table -12
Runoff Curve Numbers
Curve numbers for
-- -------------C'r�wtr lkcrip�it>rti --------------------------
-- —L�yllrulslgie sail gr�1P--- -
AYcrakc
Ir avcr typc and hydrologi a cued i 6011 iii5�rt4'i�Yu�,arCu A $ L' I
'FAY den-eli ed whalr-ur vas (w -gelalk,n e.xwhf phed)
Opc;i spmx(Isuais,parks, *alf courses.cernalerks.cle,} 5v-
Poor condition (grass cover< 3 ia)............................ bpi 79 86 89
F air vandifion I grates cow 50% to 7M.................... 49 69 79 R4
GoM caiiditlan(gra_s.,over>75%)-------------------........ 34 61 74 80
P;1 vd parking]at!;,roofs,drivrwxys.E4r.
(excluding ri hl-of-wa )............................,,.,..,.. 98 48 99 48
SIrew and roads:
Parrs& curbs and storm scwcrs(cxcluding
right-cf-way)...,,,.,.,,,,,,,,,,,,,,,,,,,,,.--.................... 98 9?: 9H 98
Paved.ap4i &fi�hts(Iris luding rjpt-af vray} .... 83 8is 92 93
Gravet(including right,I'-way).......................... 76 8S 89 91
DO{indudirig righi-or-way] .............................. 72 82 R7 get
Urban dratncts:
Commcrcial and business„,,,,,,.,............................... , 85 89 92 94 95
lnduStrial................................,,,,,................................ 72 81 88 l 93
Resi&nval digricts key airtrige lc sixlw
Ii� acm or lcs&(t#tivr! hcascSI.-. •-------...---............. 65 77 95 90 92
1.4 acrr.....-------------------------.............._. _ ........ 38 61 _ 83 87
111 acre,,............................,.-..........................__......... 30 57 81 86
I�2 acre,,,,...........................,,... ..............................,,.. 25 54 71, 80 SS
Iacrc,,,,,,.—....................................,............................ 20 51 6S. 79 M
................,,,, 13 46 65 77 ST
AgF#cu l rrrf bawds
Pasture, grassland or range i con wwous for age for gazingl'
Poor hydrologic condition....."I'll-,............................ 68 79 86 \4)
Fair h}dmlogiccondil Pon............................................ 79 H4
GJn~W hydrV19.9i-C c(widilion .......................................... 39 fit 74 NO
W
Poor hydrolcP& can itran.,,....--•-------------........................................... 45 w, r
8.3
Fair hydra ogic co ilion„,-....-.--------------............................... 6 6I] 73 79
{pDod hydrolo4ic cwrdition ....-.-.....................,,.,.,,., M r 77
Nc u'ly graded
(I Vious arm Ofily.r�o Vqa>ilIUd)-,,,,,,,,,,,,,,,,,--,,.... NO 91 94
1 Mwaie nanoff"L"iion,and la- IF,2S.
2 TIw at•rrio pemm mkpm arts shown wda wTd 404C%'el*p ilr{C+Mp):+ic CN'J.11DACr tsrllmpliafk�WC&I follMV$!impar+'kK*ArM
"dlrms yconncsicd w ihe*minage 4pirm ampmi.o sarm have a of".and prrviuw armor air cimriderc4 equivalerrt co apen
tipara in goad hydrolo it cmWliion,
I :�Thow"arc Oviv*lepl NoIhaac a1,rm-% rc.Cwr iw(N'a may 1 e w"cd fog odor vmibanwlim orapo Ip�woca "lypc'
4 Pax:Fewil biker,mull hers,mid bnjAaw desrroyrd by hemN g,=ing 4r regvtar huming.
Fsir: Woo&arc grazed Irill rLw burued ind skifix fin€I Boer c-avers Ihr>oil.
l}m d: Wo ds arc pnAceled from graai.ag-and I1cL{[,ind brush Adegostety 4ovrr Ute sail,

COMPOSITE CURVE NUMBER CALCULATIONS
DA1-STREAM CROSSING AT ROAD
SOIL GROUP COVER TYPE ACRES % CN %of DA
B Pvmt/Sidewalk/Equipment pads 13.43 0.18 98 0.97
Woods 28.21 0.39 66
Grass 130.99 0.43 79
D lWoods 12.10 11.00 183 10.03
COMPOSITE (B) 77.5
COMPOSITE (D) 83.0
TOTAL COMPOSITE CN 78
DA2-CROSSING AT ROAD
SOIL GROUP COVER TYPE ACRES % JCN %of DA
B Pvmt/Sidewalk/Equipment pads 0.06 0.02 198 11.00
Grass 2.44 0.98 179
TOTAL COMPOSITE CN 79
DA3-CROSSING AT ROAD
SOIL GROUP COVER TYPE ACRES % CN %of DA
B Pvmt/Sidewalk/Equipment pads 0.13 0.02 98 1.00
Woods 0.68 0.12 66
Grass 14.77 0.85 79
TOTAL COMPOSITE CN 78
DA4-STREAM CROSSING AT RAILROAD
SOIL GROUP COVER TYPE ACRES % CN %of DA
B Pvmt/Sidewalk/Equipment pads 14.74 0.10 98 0.96
Woods 55.09 0.38 66
Grass 75.95 0.52 79
D Woods 3.87 0.96 83 0.04
Grass 0.16 10.04 189
COMPOSITE (B) 76.0
COMPOSITE (D) 83.2
TOTAL COMPOSITE CN 76
DA5-CROSSING AT RAIL SOUTH
SOIL GROUP COVER TYPE ACRES % CN %of DA
B Pvmt 1.06 0.07 98 1.00
Woods 1.30 0.09 66
Grass 111.86 0.83 79
TOTAL COMPOSITE CN I79

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA1-Stream Crossing at Road PREPARED BY: FLS
Drainage Area Info IM Drainage Area Tc Summary Data
DRAINAGE AREA ID: DA 1 Flow Type Length(ft) Elev.Diff. Tc
TOTAL BASIN LENGTH: 1980.7 ft Sheet Flow 100.0 0.50 17.4 mins.
TOTAL ELEVATION UP: 888.00 Shallow Concentrated Flow 1880.7 55.50 10.8 mins.
TOTAL ELEVATION DOWN: 832.00 Channel Flow-Rectangular 0.0 0.00 0.0 mins.
TOTAL ACRES: 74.73 Channel Flow-Triangular 0.0 0.00 0.0 mins.
Channel Flow-Trapezoidal 0.0 0.00 1 0.0 mins.
Channel Flow-Circular 0.0 0.00 0.0 mins.
Basin Totals1980.7 56.0028.1 mins.
This time of concentration calculation is based on survey data,aerial photography,and field investigation.
2. SHALLOW CONCENTRATED FLOW
Segment#1 Segment#2 Segment#3
Surface Description Grass Segment#1 Segment#2 Segment#3
Manning's"n" 0.16 Surface Description Paved Unpaved
2-Year,24-Hr.Rain Fall(In) 3.43 Flow Length(ft) 468.3 ft 1412.4 ft
Flow Length(ft) 100.0 ft Elevation Up(ft) 887.50 872.00
Elevation Up(ft) 888.00 Elevation Down(ft) 872.00 832.00
Elevation Down(ft) 887.50 Watercourse Slope(ft/ft) 0.033 0.028
Land Slope(ft/ft) 0.005 Average Velocity(ft/Sec) 3.7 2.7
Time Of Concentration(Mins) 17.35 Time Of Concentration(Mins) 2.11 8.67
Total Sheet Flow Tc(Minutes): 17.4 min. Total Shallow Concentrated Tc(Mins):j 10.8 min.
cApw rking\east01\d2277368\
PLI TOC.Asm DA 1-Road 4 of]8

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA1-Stream Crossing at Road PREPARED BY: FLS
3. CHANNEL FLOW-RECTANGULAR CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Bottom Width(ft)
Depth(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"n"
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Rectangular Channel Tc(Mins): 0.0 mins.
4. CHANNEL FLOW-TRIANGULAR CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Top Width(ft)
Depth(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Triangular Channel Tc 0.0 min.
cApw rking\east01\d2277368\
PLI TOCAsm DA 1-Road 5 of 18

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA1-Stream Crossing at Road PREPARED BY: FLS
5. CHANNEL FLOW-TRAPEZOIDAL CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Bottom Width(ft)
Depth(ft)
Side Slopes(?H:1V)(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Trapezoidal Channel Tc 0.0 min.
6. CHANNEL FLOW-CIRCULAR CHANNEL(Gravity Flow)
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Pipe Diameter(In)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"n"
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Circular Channel Tc(Mins): 0.0 min.
7.Total Basin Time of Concentration (Mintues)
Total Basin Tc(Mins): 28.1 min.
cApw rking\east01\d2277368\
Pu TOCAsm DA 1-Road 6 of]8

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA2-Crossing at Road PREPARED BY: FLS
Drainage Area Infor 1. M Drainage Area Tc Summary Data
DRAINAGE AREA ID: DA 2 Flow Type Length(ft) Elev.Diff. Tc
TOTAL BASIN LENGTH: 367.1 ft Sheet Flow 100.0 1.00 13.1 mins.
TOTAL ELEVATION UP: 897.00 Shallow Concentrated Flow 267.1 8.00 1.6 mins.
TOTAL ELEVATION DOWN: 888.00 Channel Flow-Rectangular 0.0 0.00 0.0 mins.
TOTAL ACRES: 12.50 Channel Flow-Triangular 0.0 0.00 0.0 mins.
Channel Flow-Trapezoidal 0.0 0.00 0.0 mins.
Channel Flow-Circular 0.0 0.00 0.0 mins.
Basin Totals367.1 9.0014.7 mins.
This time of concentration calculation is based on survey data,aerial photography,and field investigation.
2. SHALLOW CONCENTRATED FLOW
Segment#1 Segment#2 Segment#3
Surface Description Grass Segment#1 Segment#2 Segment#3
Manning's"n" 0.16 Surface Description Unpaved
2-Year,24-Hr.Rain Fall(In) 3.43 Flow Length(ft) 267.1 ft
Flow Length(ft) 100.0 ft Elevation Up(ft) 896.00
Elevation Up(ft) 897.00 Elevation Down(ft) 888.00
Elevation Down(ft) 896.00 Watercourse Slope(ft/ft) 0.030
Land Slope(ft/ft) 0.010 Average Velocity(ft/Sec) 2.8
Time Of Concentration(Mins) 13.15 Time Of Concentration(Mins) 1.59
Total Sheet Flow Tc(Minutes): 13.1 min. Total Shallow Concentrated Tc(Mins):1 1.6 min.
cApw rking\east01\d2277368\
PLI TOC.Asm DA 2-Road 7 of]8

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA2-Crossing at Road PREPARED BY: FLS
3. CHANNEL FLOW-RECTANGULAR CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Bottom Width(ft)
Depth(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Rectangular Channel Tc(Mins): 0.0 mins.
4. CHANNEL FLOW-TRIANGULAR CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Top Width(ft)
Depth(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Triangular Channel Tc 0.0 min.
cApw orking\east01\d2277368\
PLI MCA— DA 2-Road 8 or 18

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA2-Crossing at Road PREPARED BY: FLS
5. CHANNEL FLOW-TRAPEZOIDAL CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Bottom Width(ft)
Depth(ft)
Side Slopes(?H:1V)(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Trapezoidal Channel Tc 0.0 min.
6. CHANNEL FLOW-CIRCULAR CHANNEL(Gravity Flow)
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Pipe Diameter(In)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"n"
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Circular Channel Tc(Mins): 0.0 min.
7.Total Basin Time of Concentration (Mintues)
Total Basin Tc(Mins): 14.7 min.
cApw rking\east01\d2277368\
PLI TOCAsm DA 2-Road 9 of 18

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA3-Crossing at Road PREPARED BY: FLS
Drainage Area Info Drainage Area Tc Summary Data
DRAINAGE AREA ID: DA 3 Flow Type Length(ft) Elev.Diff. Tc
TOTAL BASIN LENGTH: 680.7 ft Sheet Flow 100.0 2.00 10.0 mins.
TOTAL ELEVATION UP: 897.00 Shallow Concentrated Flow 580.7 25.00 2.9 mins.
TOTAL ELEVATION DOWN: 870.00 Channel Flow-Rectangular 0.0 0.00 0.0 mins.
TOTAL ACRES: 15.59 Channel Flow-Triangular 0.0 0.00 0.0 mins.
Channel Flow-Trapezoidal 0.0 0.00 0.0 mins.
Channel Flow-Circular 0.0 0.00 0.0 mins.
Basin Totals •:i 12.9 mins.
This time of concentration calculation is based on survey data,aerial photography,and field investigation.
2. SHALLOW CONCENTRATED FLOW
Segment#1 Segment#2 Segment#3
Surface Description Grass Segment#1 Segment#2 Segment#3
Manning's"n" 0.16 Surface Description Unpaved
2-Year,24-Hr.Rain Fall(In) 3.43 Flow Length(ft) 580.7 ft
Flow Length(ft) 100.0 ft Elevation Up(ft) 895.00
Elevation Up(ft) 897.00 Elevation Down(ft) 870.00
Elevation Down(ft) 895.00 Watercourse Slope(ft/ft) 0.043
Land Slope(ft/ft) 0.020 Average Velocity(ft/Sec) 3.3
Time Of Concentration(Mins) 9.97 Time Of Concentration(Mins) 2.89
Total Sheet Flow Tc(Minutes): 10.0 min. Total Shallow Concentrated Tc(Mins):1 2.9 min.
cApw rking\east01\d2277368\
PLI TOC.Asm DA 3-Road 10 of 18

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA3-Crossing at Road PREPARED BY: FLS
3. CHANNEL FLOW-RECTANGULAR CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Bottom Width(ft)
Depth(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Rectangular Channel Tc(Mins): 0.0 mins.
4. CHANNEL FLOW-TRIANGULAR CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Top Width(ft)
Depth(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Triangular Channel Tc 0.0 min.
cApw orking\east01\d2277368\
PLI MCA— DA 3-Road I I or 18

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA3-Crossing at Road PREPARED BY: FLS
5. CHANNEL FLOW-TRAPEZOIDAL CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Bottom Width(ft)
Depth(ft)
Side Slopes(?H:1V)(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Trapezoidal Channel Tc 0.0 min.
6. CHANNEL FLOW-CIRCULAR CHANNEL(Gravity Flow
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Pipe Diameter(In)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Circular Channel Tc(Mins): 0.0 min.
PLBasin Time of Concentration(Mintues)
Total Basin Tc(Mins): 12.9 min.
cApw rking\east01\d2277368\
PLI TOCAsm DA 3-Road 12 of]8

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA4-Stream Crossing at Railroad PREPARED BY: FLS
Drainage Area Info Drainage Area Tc Summary Data
DRAINAGE AREA ID: DA 4 Flow Type Length(ft) Elev.Diff. Tc
TOTAL BASIN LENGTH: 3117.8 ft Sheet Flow 100.0 0.50 17.4 mins.
TOTAL ELEVATION UP: 888.00 Shallow Concentrated Flow 730.3 25.50 3.5 mins.
TOTAL ELEVATION DOWN: 810.00 Channel Flow-Rectangular 0.0 0.00 0.0 mins.
TOTAL ACRES: 149.81 Channel Flow-Triangular 2287.5 52.00 6.8 mins.
Channel Flow-Trapezoidal 0.0 0.00 0.0 mins.
Channel Flow-Circular 0.0 0.00 0.0 mins.
Basin Totals3117.8 78.0027.7 mins.
This time of concentration calculation is based on survey data,aerial photography,and field investigation.
2. SHALLOW CONCENTRATED FLOW
Segment#1 Segment#2 Segment#3
Surface Description Grass Segment#1 Segment#2 Segment#3
Manning's"n" 0.16 Surface Description Paved Unpaved
2-Year,24-Hr.Rain Fall(In) 3.43 Flow Length(ft) 468.3 ft 262.0 ft
Flow Length(ft) 100.0 ft Elevation Up(ft) 887.50 872.00
Elevation Up(ft) 888.00 Elevation Down(ft) 872.00 862.00
Elevation Down(ft) 887.50 Watercourse Slope(ft/ft) 0.033 0.038
Land Slope(ft/ft) 0.005 Average Velocity(ft/Sec) 3.7 3.2
Time Of Concentration(Mins) 17.35 Time Of Concentration(Mins) 2.11 1.39
Total Sheet Flow Tc(Minutes): 17.4 min. Total Shallow Concentrated Tc(Mins):1 3.5 min.
cApw rking\east01\d2277368\
PLI TOCxlsm DA 4-Railroad 13 of]8

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA4-Stream Crossing at Railroad PREPARED BY: FLS
3. CHANNEL FLOW-RECTANGULAR CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Bottom Width(ft)
Depth(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"n"
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Rectangular Channel Tc(Mins): 0.0 mins.
4. CHANNEL FLOW-TRIANGULAR CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description Stream-Clean
Top Width(ft) 5.0
Depth(ft) 1.5
Area(Sq.ft) 3.8
Wetted Perimeter(ft) 5.8
Hydraulic Radius(ft) 0.6
Flow Length(ft) 2287.5
Elevation Up(ft) 862.00
Elevation Down(ft) 810.00
Channel Slope(ft/ft) 0.023
Manning's"no 0.030
Average Velocity(ft/Sec) 5.6
Time Of Concentration(Mins) 6.84
Total Triangular Channel Tc 6.8 min.
cApw rking\east01\d2277368\
PLI TOCAsm DA 4-Railroad 14 of 18

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA4-Stream Crossing at Railroad PREPARED BY: FLS
5. CHANNEL FLOW-TRAPEZOIDAL CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Bottom Width(ft)
Depth(ft)
Side Slopes(?H:1V)(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Trapezoidal Channel Tc 0.0 min.
6. CHANNEL FLOW-CIRCULAR CHANNEL(Gravity Flow)
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Pipe Diameter(In)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"n"
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Circular Channel Tc(Mins): 0.0 min.
7.Total Basin Time of Concentration (Mintues)
Total Basin Tc(Mins): 27.7 min.
cApw rking\east01\d2277368\
PLI TOCAsm DA 4-Railroad 15 of 18

12/10/2021
Time of Concentration Worksheet F:)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA5-Stream Crossing at Railroad PREPARED BY: BSS
Drainage Area Info Drainage Area Tc Summary Data
DRAINAGE AREA ID: DA 5 Flow Type Length(ft) Elev.Diff. Tc
TOTAL BASIN LENGTH: 1025.0 ft Sheet Flow 100.0 1.50 11.2 mins.
TOTAL ELEVATION UP: 915.00 Shallow Concentrated Flow 925.0 34.50 4.9 mins.
TOTAL ELEVATION DOWN: 879.00 Channel Flow-Rectangular 0.0 0.00 0.0 mins.
TOTAL ACRES: 14.22 Channel Flow-Triangular 0.0 0.00 0.0 mins.
Channel Flow-Trapezoidal 0.0 0.00 0.0 mins.
Channel Flow-Circular 0.0 0.00 0.0 mins.
Basin Totals1025.0 36.0016.1 mins.
This time of concentration calculation is based on survey data,aerial photography,and field investigation.
2. SHALLOW CONCENTRATED FLOW
Segment#1 Segment#2 Segment#3
Surface Description Grass Segment#1 Segment#2 Segment#3
Manning's"n" 0.16 Surface Description Unpaved
2-Year,24-Hr.Rain Fall(In) 3.43 Flow Length(ft) 925.0 ft
Flow Length(ft) 100.0 ft Elevation Up(ft) 913.50
Elevation Up(ft) 915.00 Elevation Down(ft) 879.00
Elevation Down(ft) 913.50 Watercourse Slope(ft/ft) 0.037
Land Slope(ft/ft) 0.015 Average Velocity(ft/Sec) 3.1
Time Of Concentration(Mins) 11.18 Time Of Concentration(Mins) 4.95
Total Sheet Flow Tc(Minutes): 11.2 min. Total Shallow Concentrated Tc(Mins):1 4.9 min.
cApw rking\east01\d2277368\
PLI TOCxlsm DA 5-Railroad South 16 ofls

12/10/2021
Time of Concentration Worksheet K)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA5-Stream Crossing at Railroad PREPARED BY: BSS
3. CHANNEL FLOW-RECTANGULAR CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Bottom Width(ft)
Depth(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"n"
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Rectangular Channel Tc(Mins): 0.0 rains.
4. CHANNEL FLOW-TRIANGULAR CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Top Width(ft)
Depth(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Triangular Channel Tc 0.0 min.
cApw rking\east01\d2277368\
PLI TOCAsm DA 5-Railroad South 17 of1s

12/10/2021
Time of Concentration Worksheet K)R
SCS TR-55 Method
PROJECT: PLI DATE: 12/10/21
SCENARIO: DA5-Stream Crossing at Railroad PREPARED BY: BSS
5. CHANNEL FLOW-TRAPEZOIDAL CHANNEL
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Bottom Width(ft)
Depth(ft)
Side Slopes(?H:1V)(ft)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"no
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Trapezoidal Channel Tc 0.0 min.
6. CHANNEL FLOW-CIRCULAR CHANNEL(Gravity Flow)
Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7 Segment#8 Segment#9
Surface Description
Pipe Diameter(In)
Area(Sq.ft)
Wetted Perimeter(ft)
Hydraulic Radius(ft)
Flow Length(ft)
Elevation Up(ft)
Elevation Down(ft)
Channel Slope(ft/ft)
Manning's"n"
Average Velocity(ft/Sec)
Time Of Concentration(Mins)
Total Circular Channel Tc(Mins): 0.0 min.
7.Total Basin Time of Concentration (Mintues)
Total Basin Tc(Mins): 16.1 min.
cApw rking\east01\d2277368\
PLI TOCAsm DA 5-Railroad South 18 ores

PLC Lithium Hydroxide Conversion Plant ���
Appendices
Appendix F — NOAA Rainfall
Data

Precipitation Frequency Data Server Page 1 of 4
NOAA Atlas 14,Volume 2,Version 3
Location name: Lincolnton,North Carolina,USA' '
Latitude:35.4667°,Longitude: -81.3333°
Elevation:919.07 ft"
'source:ESRI Mapsk,,�
*'source:USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M.Bonnin,D.Martin,B.Lin,T.Parzybok,M.Yekta,and D.Riley
NOAA,National Weather Service,Silver Spring,Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90%confidence intervals(in inches/hour)'
Average recurrence interval(years)
11 2 11 5 10 11 25 11 50 1 100 200 500 1000
5-min 4.67 5.52 6.49 7.24 8.15 8.81 9.46 10.1 10.9 11.5
(4.28-5.08) 1 (5.06 6.02) 1 (5.95-7.09) (6.60-7.88) (7.39-8.88) (7.94 9.61) 1 (8.48-10.3) (8.96-11.1) (9.54-12.0) (9.96-12.7)
10-min 8.00 8.60 9.04
(7.10-8.77) (7.55-9.47) (7.85-10.0)
15-min 3.10 3.70 4.39 4.88 5.48 5.92 6.34 6.72 7.22 7.56
(2.85-3.38) 1 (3.40-4.04) (4.02-4.79) (4.46-5.32) (4.98-5.98) (5.34-6.46) 1 (5.68-6.92) (5.98-7.37) (6.33-7.95) (6.56-8.38)
30-min 2.13 2.55 3.12 3.54 4.06 4.46 4.85 5.23 5.74 6.13
(1.95-2.32) 1 (2.35-2.79) 1 (2.85-3.40) 1 (3.23-3.85) 1 (3.68-4.43) 1 (4.02-4.86) 1 (4.35-5.30) (4.65-5.74) 1 (5.04-6.32) 1 (5.32-6.78)
60-min 1.33 1.60 2.00 2.30 2.70 3.02 3.34 3.67 4.12 4.47(1.22-1.45) (1.47-1.75) (1.83-2.18) (2.10-2.51) 1 (2.45-2.95) (2.72-3.30) (2.99-3.65) (3.26-4.02) 1 (3.61-4.54) (3.88-4.95)
2-hr 0.770 0.935 1.17 1.36 1.62 1.83 2.04 2.26 2.58 2.83
(0.706-0.843) (0.856-1.02) (1.07-1.29) 1 (1.24-1.49) 11 (1.47-1.77) (1.64-2.00) (1.82-2.24) 1 (2.00-2.49) 1 (2.25-2.85) 1 (2.44-3.15)
3-hr 0.549 0.664 0.837 0.975 1.17 1.33 1.50 1.68 1.94 2.15
(0.503-0.605) (0.608-0.732) (0.764-0.921) (0.886-1.07) 1 (1.06-1.29) 1 (1.19-1.46) 1 (1.33-1.65) 1 (1.48-1.86) 1 (1.67-2.15) 1 (1.83-2.40)
6-hr 0.339 0.408 0.512 0.595 0.714 0.812 0.916 1.03 1.19 1.32
(0.312-0.370)(0.376-0.447) (0.469-0.560) (0.544-0.650) (0.647-0.779) (0.731-0.887) (0.817-1.00) (0.907-1.13) 1 (1.03-1.31)
12-hr 0.205 0.248 0.310 0.361 0.431 0.490 0.551 0.616 0.708 0.784
(0.189-0.223)(0.228-0.270) (0.285-0.338) (0.330-0.393) (0.392-0.470) (0.442-0.533)(0.493-0.599) (0.545-0.671)(0.618-0.774) (0.675-0.860)
24-hr 0.124 0.150 0.189 0.220 0.262 0.296 0.331 0.367 0.416 0.456
(0.116-0.133)(0.140-0.161) (0.176-0.203) (0.205-0.236) (0.243-0.281) (0.274-0.317) (0.304-0.354) (0.336-0.393)(0.380-0.447) (0.414-0.490)
2-day 0.69-0 079 0.8 -0 096 0.104-0 120 0.120-0.9138 0.14170.3164 0.159-0.2184 0.1076-0 205 0.194-0 227 0.2118-0 257 0.2372--0 281
3-day 0.052 0.063 0.078 0.090 0.106 0.119 0.133 0.146 0.165 0.180
(0.049-0.056)(0.059-0.067) (0.073-0.084) (0.084-0.097) (0.099-0.114) (0.110-0.128)(0.122-0.142) (0.135-0.157)(0.151-0.178) (0.164-0.194)
4-day 0.041 0.050 0.061 0.071 0.083 0.093 0.104 0.114 0.128 0.140
(0.039-0.044)(0.046-0.053) (0.057-0.066) (0.066-0.076) (0.077-0.089) (0.086-0.100)(0.095-0.111) (0.105-0.122)(0.118-0.138) (0.127-0.150)
7-day 0.027 0.033 0.040 0.045 0.053 0.059 0.065 0.072 0.080 0.087
(0.026-0 029)(0.031-0.035) (0.037-0.042) (0.043-0.048) (0.050-0.057) (0.055-0.063)(0.061-0.070) (0.066-0.076)(0.074-0.086) (0.080-0.093)
0.041
10-day 0 021--0 023 0.02 -0 028 0.030-0 033 0.03 -0 038 0.038-0 043 0.04 -0 048 0.046-0 052 0050-0 057 0.05 -0 063 0060-0 068
20-day 0.015 0.017 0.020 0.023 0.026 0.029 0.031 0.034 0.037 0.040
(0.014-0.015)(0.016-0.018) (0.019-0.021) (0.022-0.024) (0.025-0.028) (0.027-0.030)(0.029-0.033) (0.032-0.036)(0.035-0.040) (0.037-0.043)
30-day 0.012 0.014 0.016 0.018 0.020 0.022 0.024 0.025 0.028 0.029
(0.011-0.013)(0.013-0.015) (0.016-0.017) (0.017-0.019) (0.019-0.021) (0.021-0.023)(0.022-0.025) (0.024-0.027)(0.026-0.029) (0.028-0.031)
45-day 0.010 0.012 0.013 0.015 0.016 0.017 0.019 0.020 0.021 0.022
(0.010-0.011)(0.011-0.012) (0.013-0.014) (0.014-0.015) (0.016-0.017) (0.017-0.018)(0.018-0.020) (0.019-0.021)(0.020-0.022) (0.021-0.024)
60-day 0.009 0.010 0.012 0.013 0.014 0.015 0.016 0.017 0.018 0.019
(0.009-0009)(0.010-0.011) (0.011-0.012) (0.012-0.013) (0.014-0.015) (0.015-0.016)(0.015-0.017) (0.016-0.018)(0.017-0.019) (0.018-0.020)
Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates
(for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds
are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PIMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to to Too
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Precipitation Frequency Data Server Page 2 of 4
PF graphical
PD5-based intensity-duration-frequency (IDF)curves
Latitude: 35.4667 Longitude: -81.3333'
100.000
Average recufrence
inlerral
r
10.000 ... (Years}
c
— 1
Z' 2
1.000 _. ..:......:
a - - — 5
O — 25
+, 0.100 ----- ----•------- - - —
49 5 0
200
4 a _0.010 ...........'........... ...
500
1000
0-001
� s s s r m mm m m m ru FUm
N A 6 N A - --4 7 -V -y -y -y-y
u'] O v1 O O �"1 N N V A A OO OO OO Un OO
ri rl rn lG Duration ri INrn -T�Q
100.000
r
10.000
- Duration
41
1.000 - ---- ----- --- - ---- — 5-min — 2-day
a c — 1Dmin — 3-day
15min — 4-day
0.100 — 3"Or — 7Aay
— 6Dmin — 10-aay
EL
Ld — 2-rr — 20-day
a 0.010 .. . . -- . . . ........ .........:...... — 3a1r — 30 oay
— 5a1r — 45-day
12-hr — 60-day
0-001 — 24<-hr
1 2 5 10 25 50 100 200 500 1000
Average recurrence interval [years]
NOAAAtIas 14,Volume 2,Version 3 Created{GMT}: Fri Aug 20 14:36:00 2021
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Maps & aerials
Small scale terrain
�r
I Lincoln
Large scale terrain
Kingsport' Bristol
il
Johnson City' 3
sti Winston-Salem
M • • Dui
Greensboro
r„il Mitd,eii
rtw� Ashelille _ILA RT H C A R O L I N A
Charlotte ttev
Greenville
100km
SOUTH CAROLINA
60mi
Large scale map
Kinasoort Bri tol
Johnson City
nston� lem Gmensbon
A rhie;Mlle I I North
Carolina a
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4
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North
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National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring,MD 20910
Questions?:HDSC.Questions(a.noaa.aov
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PLC Lithium Hydroxide Conversion Plant ���
Appendices
Appendix G — Sediment
Basin Calculations

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Riser Sediment Basin: SB-201
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)1 11.16 ac 10 Yr Peak Flow(Q10) 48.61 cfs
Disturbed area(DA) 6.68 ac 25 Yr Peak Flow(Q25) 54.77 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 23,826 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (1800 cf per ac of TDA)5 20,088 cf
10 Yr Storm Rainfall Intensity(i)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)4 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 832.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.50 ft 832.00 0.00 20,173 0
Depth of Flow over Riser(1 ft min)5 1.00 ft 833.00 1.00 22,098 21,128
Depth of Flow over Emergency Spillway 0.50 ft 834.00 2.00 24,079 44,210
25 Yr Storm Freeboard(1 ft req'd)5 1.00 ft 835.00 3.00 26,116 69,300
836.00 4.00 28,211 96,457
Basin Configuration 837.00 5.00 30,362 125,737
Bottom Elevation 832.00 msl
Sediment Storage Elevation 834.50 msl
Riser Crest 834.50 msl
Emergency Spillway Crest 835.50 msl
Top of Berm 837.00 msl
Skimmer Outlet Basin Size Check
Desired Skimmer Drawdown Time(td)6 72 hrs Basin Surface Area Provided at Spillway Crest 25,098 sf
Desired Skimmer Drawdown Rate(Qd) 6,696 ft3/day Basin Storage Volume Provided Below Spillway Crest 56,503 cf
Skimmer Size 5.0 in
Head on Orifice(H)5 0.333 ft
Calculated Orifice Diameter' 2.241 in
Actual Orifice Diameter' 2.250 in
Actual Skimmer Drawdown Time' 71 hrs
Barrel
Riser Diameter(15 in min)5 36 in Riser Flow as Weir13 29.22 cfs
Barrel Diameter' 18 in Riser Flow as Orifice14 34.04 cfs
Barrel Invert Elevation 831.50 msl
Barrel Length 50.00 ft Barrel Flow as Orifice14 15.34 cfs
Barrel Manning's N10 0.025 Barrel Flow as Pipe15 11.03 cfs
Sharp Crested Weir Coefficient(C)11 3.1
Orifice Coefficient(C)12 0.6 Controlling Flow through Riser and Barrel Spillway 11.03 cfs
Barrel
Riser Diameter(15 in min)5 72 in Riser Flow as Weir13 58.43 cfs
Barrel Diameter' DOUBLE 24 in Riser Flow as Orifice14 136.14 cfs
Barrel Invert Elevation 831.50 msl
Barrel Length 50.00 ft Barrel Flow as Orifice14 DOUBLE 52.40 cfs
Barrel Manning's N10 0.025 Barrel Flow as Pipe15 DOUBLE 42.13 cfs
Sharp Crested Weir Coefficient C 11 3.1
Orifice Coefficient(C)12 0.6 Controlling Flow through Riser and Barrel Spillway 42.13 cfs
Total of controlling Barrel Flows 53.17 cfs
Spillway
Minimum Allowable Spillway Length16 20 ft Difference b/n 25 Yr Peak Flow and Riser/Barrel Flow 1.61 cfs
Broad Crested Weir Coefficient(C)17 2.80 Ell Design Spillway Length13 20 ft
Page 1 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.:1 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Concrete
Length of Exposed Outlet Pipe 10 ft Buoyancy's 6371 Ibs
Concrete Anchor Width 7.0 ft Weight of Concrete Anchor 7105 Ibs
Concrete Anchor Length 7.0 ft
Concrete Anchor Thickness 1.00 ft Safety Factor" 1.1
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.61-Sediment Basin of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
7.Skimmer orifice equatic
D=�%i(2310-VC H) (inches) (see note 5)
8.Actual skimmer orifice diameter is rounded to the nearest 1/4 inch.
9.Riser cross-sectional area is required to be more than 1.5 times the barrel cross-sectional area.
10.Use 0.025 for CMP and 0.013 for RCP.
11.3.1 for corrugated metal pipe risers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
12.0.6 for corrugated metal nine ricers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
13.Weir equation: Q= CLH'� (see note 11)
14.Orifice equation: Q=CA(2gH)Ps (see note 12)
15.Pipe Flow equation: 2gh �9-5 'See
+
Q=a [tKm+KPL
16.Minimum allowable emergency spillway length is 20 feet(see note 5).
17.2.80 is the maximum allowable coefficient per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
18.Weight of water displaced by riser and exposed outlet pipe.
19.Minimum safety factor is 1.1 per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
Page 2 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Riser Sediment Basin: SB-202
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)1 5.65 ac 10 Yr Peak Flow(Q10) 24.61 cfs
Disturbed area(DA) 5.79 ac 25 Yr Peak Flow(Q25) 27.73 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 12,063 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (1800 cf per ac of TDA)5 10,170 cf
10 Yr Storm Rainfall Intensity(i)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)4 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 825.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.50 ft 825.00 0.00 9,393 0
Depth of Flow over Riser(1 ft min)5 1.00 ft 826.00 1.00 11,000 10,186
Depth of Flow over Emergency Spillway 0.50 ft 827.00 2.00 12,665 22,009
25 Yr Storm Freeboard(1 ft req'd)5 1.00 ft 828.00 3.00 14,386 35,525
829.00 4.00 16,162 50,790
Basin Configuration 830.00 5.00 17,996 67,861
Bottom Elevation 825.00 msl
Sediment Storage Elevation 827.50 msl
Riser Crest 827.50 msl
Emergency Spillway Crest 828.50 msl
Top of Berm 830.00 msl
Skimmer Outlet Basin Size Check
Desired Skimmer Drawdown Time(td)6 72 hrs Basin Surface Area Provided at Spillway Crest 13,526 sf
Desired Skimmer Drawdown Rate(Qd) 3,390 ft3/day Basin Storage Volume Provided Below Spillway Crest 28,555 cf
Skimmer Size 8.0 in
Head on Orifice(H)5 0.500 ft
Calculated Orifice Diameter' 1.441 in
Actual Orifice Diameter' 1.500 in
Actual Skimmer Drawdown Time' 66 hrs
Barrel
Riser Diameter(15 in min)5 72 in Riser Flow as Weir13 58.43 cfs
Barrel Diameter' DOUBLE 24 in Riser Flow as Orifice14 136.14 cfs
Barrel Invert Elevation 824.00 msl
Barrel Length 50.00 ft Barrel Flow as Orifice14 56.60 cfs
Barrel Manning's N10 0.025 Barrel Flow as Pipe15 45.51 cfs
Sharp Crested Weir Coefficient(C)11 3.1
Orifice Coefficient(C)12 0.6 Controlling Flow through Riser and Barrel Spillway 45.51 cfs
Spillway
Minimum Allowable Spillway Length16 20 ft Difference b/n 25 Yr Peak Flow and Riser/Barrel Flow -17.78 cfs
Broad Crested Weir Coefficient(C)17 2.80 Ell Design Spillway Length" 20 ft
Concrete
Length of Exposed Outlet Pipe 10 ft Buoyancy18 6371 Ibs
Concrete Anchor Width 6.5 ft Weight of Concrete Anchor 9189 Ibs
Concrete Anchor Length 6.5 ft
Concrete Anchor Thickness 1.50 ft Safety Factor19 1.4
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
Page 3 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,hftp://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.61-Sediment Basin of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
7.Skimmer orifice equatic I
D= V Qa/(2370*V H) (inches) (see note 5)
8.Actual skimmer orifice diameter is rounded to the nearest 1/4 inch.
9.Riser cross-sectional area is required to be more than 1.5 times the barrel cross-sectional area.
10.Use 0.025 for CMP and 0.013 for RCP.
11.3.1 for corrugated metal pipe risers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
12.0.6 for corrugated mortal nine ricers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
13.Weir equation: Q= CLH7 5 (see note 11)
14.Orifice equation: Q=CA(2gH)R5 (see note 12)
15.Pipe Flow equation: 2gh O5 *See
Q=a [1+Km+KPL
16.Minimum allowable emergency spillway length is 20 feet(see note 5).
17.2.80 is the maximum allowable coefficient per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
18.Weight of water displaced by riser and exposed outlet pipe.
19.Minimum safety factor is 1.1 per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
Page 4 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Riser Sediment Basin: SB-203
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)1 3.93 ac 10 Yr Peak Flow(Q10) 17.12 cfs
Disturbed area(DA) 3.93 ac 25 Yr Peak Flow(Q25) 19.29 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 8,390 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (1800 cf per ac of TDA)5 7,074 cf
10 Yr Storm Rainfall Intensity i 4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)4 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 808.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.50 ft 808.00 0.00 5,874 0
Depth of Flow over Riser(1 ft min)5 1.00 ft 809.00 1.00 7,118 6,486
Depth of Flow over Emergency Spillway 0.50 ft 810.00 2.00 8,435 14,253
25 Yr Storm Freeboard(1 ft req'd)5 1.00 ft 811.00 3.00 9,809 23,367
812.00 4.00 11,239 33,882
Basin Configuration 813.00 5.00 12,726 45,857
Bottom Elevation 808.00 msl
Sediment Storage Elevation 810.50 msl
Riser Crest 810.50 msl
Emergency Spillway Crest 811.50 msl
Top of Berm 813.00 msl
Skimmer Outlet Basin Size Check
Desired Skimmer Drawdown Time(td)6 72 hrs Basin Surface Area Provided at Spillway Crest 9,122 sf
Desired Skimmer Drawdown Rate(Qd) 2,358 ft'/day Basin Storage Volume Provided Below Spillway Crest 18,641 cf
Skimmer Size 6.0 in
Head on Orifice(H)5 0.417 ft
Calculated Orifice Diameter' 1.257 in
Actual Orifice Diameter' 1.250 in
Actual Skimmer Drawdown Time' 73 hrs
Barrel
Riser Diameter(15 in min)5 48 in Riser Flow as Weir13 38.96 cfs
Barrel Diameter' 24 in Riser Flow as Orifice14 60.51 cfs
Barrel Invert Elevation 807.50 msl
Barrel Length 50.00 ft Barrel Flow as Orifice14 26.20 cfs
Barrel Manning's N10 0.025 Barrel Flow as Pipe15 21.07 cfs
Sharp Crested Weir Coefficient(C)11 3.1
Orifice Coefficient(C)12 0.6 Controlling Flow through Riser and Barrel Spillway 21.07 cfs
Spillway
Minimum Allowable Spillway Length16 20 ft Difference b/n 25 Yr Peak Flow and Riser/Barrel Flow -1.78 cfs
Broad Crested Weir Coefficient(C)17 2.80 Ell Design Spillway Length" 20 ft
Concrete
Length of Exposed Outlet Pipe 10 ft Buoyancy18 3921 Ibs
Concrete Anchor Width 6.0 ft Weight of Concrete Anchor 5220 Ibs
Concrete Anchor Length 6.0 ft
Concrete Anchor Thickness 1.00 ft Safety Factor19 1.3
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
Page 5 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,hftp://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.61-Sediment Basin of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
7.Skimmer orifice equatic I
D= V Qa/(2370*V H) (inches) (see note 5)
8.Actual skimmer orifice diameter is rounded to the nearest 1/4 inch.
9.Riser cross-sectional area is required to be more than 1.5 times the barrel cross-sectional area.
10.Use 0.025 for CMP and 0.013 for RCP.
11.3.1 for corrugated metal pipe risers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
12.0.6 for corrugated mortal nine ricers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
13.Weir equation: Q= CLH7 5 (see note 11)
14.Orifice equation: Q=CA(2gH)R5 (see note 12)
15.Pipe Flow equation: 2gh O5 *See
Q=a [1+Km+KPL
16.Minimum allowable emergency spillway length is 20 feet(see note 5).
17.2.80 is the maximum allowable coefficient per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
18.Weight of water displaced by riser and exposed outlet pipe.
19.Minimum safety factor is 1.1 per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
Page 6 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Riser Sediment Basin: SB-204
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)1 8.00 ac 10 Yr Peak Flow(Q10) 34.85 cfs
Disturbed area(DA) 8.00 ac 25 Yr Peak Flow(Q25) 39.26 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 17,080 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (1800 cf per ac of TDA)5 14,400 cf
10 Yr Storm Rainfall Intensity(i)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)4 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 813.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.50 ft 813.00 0.00 12,899 0
Depth of Flow over Riser(1 ft min)5 1.00 ft 814.00 1.00 14,609 13,745
Depth of Flow over Emergency Spillway 0.50 ft 815.00 2.00 16,375 29,229
25 Yr Storm Freeboard(1 ft req'd)5 1.00 ft 816.00 3.00 18,198 46,507
817.00 4.00 20,007 65,603
Basin Configuration 818.00 5.00 22,013 86,605
Bottom Elevation 813.00 msl
Sediment Storage Elevation 815.50 msl
Riser Crest 815.50 msl
Emergency Spillway Crest 816.50 msl
Top of Berm 818.00 msl
Skimmer Outlet Basin Size Check
Desired Skimmer Drawdown Time(td)6 72 hrs Basin Surface Area Provided at Spillway Crest 17,287 sf
Desired Skimmer Drawdown Rate(Qd) 4,800 ft3/day 113asin Storage Volume Provided Below Spillway Crest 37,643 cf
Skimmer Size 6.0 in
Head on Orifice(H)5 0.417 ft
Calculated Orifice Diameter' 1.794 in
Actual Orifice Diameter' 1.750 in
Actual Skimmer Drawdown Time' 76 hrs
Barrel
Riser Diameter(15 in min)5 72 in Riser Flow as Weir13 58.43 cfs
Barrel Diameter' DOUBLE 24 in Riser Flow as Orifice14 136.14 cfs
Barrel Invert Elevation 812.50 msl
Barrel Length 50.00 ft Barrel Flow as Orifice14 52.40 cfs
Barrel Manning's N10 0.025 Barrel Flow as Pipe15 42.13 cfs
Sharp Crested Weir Coefficient(C)11 3.1
Orifice Coefficient(C)12 0.6 Controlling Flow through Riser and Barrel Spillway 42.13 cfs
Spillway
Minimum Allowable Spillway Length16 20 ft Difference b/n 25 Yr Peak Flow and Riser/Barrel Flow -2.87 cfs
Broad Crested Weir Coefficient(C)17 2.80 Ell Design Spillway Length" 20 ft
Concrete
Length of Exposed Outlet Pipe 10 ft Buoyancy18 6371 Ibs
Concrete Anchor Width 6.0 ft Weight of Concrete Anchor 7830 Ibs
Concrete Anchor Length 6.0 ft
Concrete Anchor Thickness 1.50 ft Safety Factor19 1.2
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
Page 7 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,hftp://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.61-Sediment Basin of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
7.Skimmer orifice equatic I
D= V Qa/(2370*V H) (inches) (see note 5)
8.Actual skimmer orifice diameter is rounded to the nearest 1/4 inch.
9.Riser cross-sectional area is required to be more than 1.5 times the barrel cross-sectional area.
10.Use 0.025 for CMP and 0.013 for RCP.
11.3.1 for corrugated metal pipe risers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
12.0.6 for corrugated mortal nine ricers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
13.Weir equation: Q= CLH7 5 (see note 11)
14.Orifice equation: Q=CA(2gH)R5 (see note 12)
15.Pipe Flow equation: 2gh O5 *See
Q=a [1+Km+KPL
16.Minimum allowable emergency spillway length is 20 feet(see note 5).
17.2.80 is the maximum allowable coefficient per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
18.Weight of water displaced by riser and exposed outlet pipe.
19.Minimum safety factor is 1.1 per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
Page 8 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Riser Sediment Basin: SB-205
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)1 4.50 ac 10 Yr Peak Flow(Q10) 19.60 cfs
Disturbed area(DA) 4.50 ac 25 Yr Peak Flow(Q25) 22.09 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 9,607 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (1800 cf per ac of TDA)5 8,100 cf
10 Yr Storm Rainfall Intensity i 4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)4 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 828.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 1.80 ft 828.00 0.00 8,809 0
Depth of Flow over Riser(1 ft min)5 1.00 ft 829.00 1.00 10,387 9,587
Depth of Flow over Emergency Spillway 0.20 ft 830.00 2.00 12,048 20,794
25 Yr Storm Freeboard(1 ft req'd)5 1.00 ft 831.00 3.00 13,778 33,698
832.00 4.00 15,576 48,366
Basin Configuration
Bottom Elevation 828.00 msl
Sediment Storage Elevation 829.80 msl
Riser Crest 829.80 msl
Emergency Spillway Crest 830.80 msl
Top of Berm 832.00 msl
Skimmer Outlet Basin Size Check
Desired Skimmer Drawdown Time(td)6 72 hrs Basin Surface Area Provided at Spillway Crest 11,716 sf
Desired Skimmer Drawdown Rate(Qd) 2,700 ft'/day Basin Storage Volume Provided Below Spillway Crest 18,423 cf
Skimmer Size 5.0 in
Head on Orifice(H)5 0.333 ft
Calculated Orifice Diameter' 1.423 in
Actual Orifice Diameter' 1.500 in
Actual Skimmer Drawdown Time' 65 hrs
Barrel
Riser Diameter(15 in min)5 48 in Riser Flow as Weir13 38.96 cfs
Barrel Diameter' 24 in Riser Flow as Orifice14 60.51 cfs
Barrel Invert Elevation 826.80 msl
Barrel Length 50.00 ft Barrel Flow as Orifice14 26.20 cfs
Barrel Manning's N10 0.025 Barrel Flow as Pipe15 21.07 cfs
Sharp Crested Weir Coefficient(C)11 3.1
Orifice Coefficient(C)12 0.6 Controlling Flow through Riser and Barrel Spillway 21.07 cfs
Spillway
Minimum Allowable Spillway Length16 20 ft Difference b/n 25 Yr Peak Flow and Riser/Barrel Flow 1.02 cfs
Broad Crested Weir Coefficient(C)17 2.80 Ell Design Spillway Length13 20 ft
Concrete
Length of Exposed Outlet Pipe 10 ft Buoyancy18 3372 Ibs
Concrete Anchor Width 6.0 ft Weight of Concrete Anchor 5220 Ibs
Concrete Anchor Length 6.0 ft
Concrete Anchor Thickness 1.00 ft Safety Factor19 1.5
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
Page 9 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,hftp://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.61-Sediment Basin of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
7.Skimmer orifice equatic I
D= V Qa/(2370*V H) (inches) (see note 5)
8.Actual skimmer orifice diameter is rounded to the nearest 1/4 inch.
9.Riser cross-sectional area is required to be more than 1.5 times the barrel cross-sectional area.
10.Use 0.025 for CMP and 0.013 for RCP.
11.3.1 for corrugated metal pipe risers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
12.0.6 for corrugated mortal nine ricers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
13.Weir equation: Q= CLH7 5 (see note 11)
14.Orifice equation: Q=CA(2gH)R5 (see note 12)
15.Pipe Flow equation: 2gh O5 *See
Q=a [1+Km+KPL
16.Minimum allowable emergency spillway length is 20 feet(see note 5).
17.2.80 is the maximum allowable coefficient per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
18.Weight of water displaced by riser and exposed outlet pipe.
19.Minimum safety factor is 1.1 per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
Page 10 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Riser Sediment Basin: SB-206
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)1 5.50 ac 10 Yr Peak Flow(Q10) 23.96 cfs
Disturbed area(DA) 5.50 ac 25 Yr Peak Flow(Q25) 26.99 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 11,742 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (1800 cf per ac of TDA)5 9,900 cf
10 Yr Storm Rainfall Intensity i 4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)4 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 833.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 1.80 ft 833.00 0.00 11,208 0
Depth of Flow over Riser(1 ft min)5 1.00 ft 834.00 1.00 12,924 12,056
Depth of Flow over Emergency Spillway 0.20 ft 835.00 2.00 14,717 25,867
25 Yr Storm Freeboard(1 ft req'd)5 1.00 ft 836.00 3.00 16,560 41,496
837.00 4.00 18,449 58,992
Basin Configuration
Bottom Elevation 833.00 msl
Sediment Storage Elevation 834.80 msl
Riser Crest 834.80 msl
Emergency Spillway Crest 835.80 msl
Top of Berm 837.00 msl
Skimmer Outlet Basin Size Check
Desired Skimmer Drawdown Time(td)6 72 hrs Basin Surface Area Provided at Spillway Crest 14,358 sf
Desired Skimmer Drawdown Rate(Qd) 3,300 ft3/day Basin Storage Volume Provided Below Spillway Crest 22,964 cf
Skimmer Size 6.0 in
Head on Orifice(H)5 0.417 ft
Calculated Orifice Diameter' 1.487 in
Actual Orifice Diameter' 1.500 in
Actual Skimmer Drawdown Time' 71 hrs
Barrel
Riser Diameter(15 in min)5 60 in Riser Flow as Weir13 48.69 cfs
Barrel Diameter' 36 in Riser Flow as Orifice14 94.54 cfs
Barrel Invert Elevation 831.00 msl
Barrel Length 50.00 ft Barrel Flow as Orifice14 61.83 cfs
Barrel Manning's N10 0.025 Barrel Flow as Pipe15 56.41 cfs
Sharp Crested Weir Coefficient(C)11 3.1
Orifice Coefficient(C)12 0.6 Controlling Flow through Riser and Barrel Spillway 48.69 cfs
Spillway
Minimum Allowable Spillway Length16 20 ft Difference b/n 25 Yr Peak Flow and Riser/Barrel Flow -21.70 cfs
Broad Crested Weir Coefficient(C)17 2.80 Ell Design Spillway Length13 20 ft
Concrete
Length of Exposed Outlet Pipe 10 ft Buoyancy18 6616 Ibs
Concrete Anchor Width 7.0 ft Weight of Concrete Anchor 10658 Ibs
Concrete Anchor Length 7.0 ft
Concrete Anchor Thickness 1.50 ft Safety Factor19 1.6
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
Page 11 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,hftp://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.61-Sediment Basin of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
7.Skimmer orifice equatic I
D= V Qa/(2370*V H) (inches) (see note 5)
8.Actual skimmer orifice diameter is rounded to the nearest 1/4 inch.
9.Riser cross-sectional area is required to be more than 1.5 times the barrel cross-sectional area.
10.Use 0.025 for CMP and 0.013 for RCP.
11.3.1 for corrugated metal pipe risers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
12.0.6 for corrugated mortal nine ricers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
13.Weir equation: Q= CLH7 5 (see note 11)
14.Orifice equation: Q=CA(2gH)R5 (see note 12)
15.Pipe Flow equation: 2gh O5 *See
Q=a [1+Km+KPL
16.Minimum allowable emergency spillway length is 20 feet(see note 5).
17.2.80 is the maximum allowable coefficient per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
18.Weight of water displaced by riser and exposed outlet pipe.
19.Minimum safety factor is 1.1 per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
Page 12 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Riser Sediment Basin: SB-207
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)1 5.79 ac 10 Yr Peak Flow(Q10) 25.22 cfs
Disturbed area(DA) 5.79 ac 25 Yr Peak Flow(Q25) 28.42 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 12,362 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (1800 cf per ac of TDA)5 10,422 cf
10 Yr Storm Rainfall Intensity(i)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)4 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 843.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.50 ft 843.00 0.00 10,116 0
Depth of Flow over Riser(1 ft min)5 1.00 ft 844.00 1.00 11,727 10,912
Depth of Flow over Emergency Spillway 0.50 ft 845.00 2.00 13,395 23,463
25 Yr Storm Freeboard(1 ft req'd)5 1.00 ft 846.00 3.00 15,119 37,712
847.00 4.00 16,900 53,713
Basin Configuration 848.00 5.00 18,737 71,523
Bottom Elevation 843.00 msl
Sediment Storage Elevation 845.50 msl
Riser Crest 845.50 msl
Emergency Spillway Crest 846.50 msl
Top of Berm 848.00 msl
Skimmer Outlet Basin Size Check
Desired Skimmer Drawdown Time(td)6 72 hrs Basin Surface Area Provided at Spillway Crest 14,257 sf
Desired Skimmer Drawdown Rate(Qd) 3,474 ft3/day Basin Storage Volume Provided Below Spillway Crest 30,375 cf
Skimmer Size 8.0 in
Head on Orifice(H)5 0.500 ft
Calculated Orifice Diameter' 1.458 in
Actual Orifice Diameter' 1.500 in
Actual Skimmer Drawdown Time' 68 hrs
Barrel
Riser Diameter(15 in min)5 48 in Riser Flow as Weir13 38.96 cfs
Barrel Diameter' 24 in Riser Flow as Orifice14 60.51 cfs
Barrel Invert Elevation 841.00 msl
Barrel Length 50.00 ft Barrel Flow as Orifice14 32.09 cfs
Barrel Manning's N10 0.025 Barrel Flow as Pipe15 25.80 cfs
Sharp Crested Weir Coefficient(C)11 3.1
Orifice Coefficient(C)12 0.6 Controlling Flow through Riser and Barrel Spillway 25.80 cfs
Spillway
Minimum Allowable Spillway Length16 20 ft Difference b/n 25 Yr Peak Flow and Riser/Barrel Flow 2.62 cfs
Broad Crested Weir Coefficient(C)17 2.80 Ell Design Spillway Length" 20 ft
Concrete
Length of Exposed Outlet Pipe 10 ft Buoyancy18 3921 Ibs
Concrete Anchor Width 5.0 ft Weight of Concrete Anchor 5438 Ibs
Concrete Anchor Length 5.0 ft
Concrete Anchor Thickness 1.50 ft Safety Factor19 1.4
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
Page 13 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,hftp://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.61-Sediment Basin of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
7.Skimmer orifice equatic I
D= V Qa/(2370*V H) (inches) (see note 5)
8.Actual skimmer orifice diameter is rounded to the nearest 1/4 inch.
9.Riser cross-sectional area is required to be more than 1.5 times the barrel cross-sectional area.
10.Use 0.025 for CMP and 0.013 for RCP.
11.3.1 for corrugated metal pipe risers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
12.0.6 for corrugated mortal nine ricers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
13.Weir equation: Q= CLH7 5 (see note 11)
14.Orifice equation: Q=CA(2gH)R5 (see note 12)
15.Pipe Flow equation: 2gh O5 *See
Q=a [1+Km+KPL
16.Minimum allowable emergency spillway length is 20 feet(see note 5).
17.2.80 is the maximum allowable coefficient per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
18.Weight of water displaced by riser and exposed outlet pipe.
19.Minimum safety factor is 1.1 per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
Page 14 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Riser Sediment Basin:
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)1 5.65 ac 10 Yr Peak Flow(Q10) 24.61 cfs
Disturbed area(DA) 5.50 ac 25 Yr Peak Flow(Q25) 27.73 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 12,063 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (1800 cf per ac of TDA)5 10,170 cf
10 Yr Storm Rainfall Intensity(i)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)4 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 874.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.50 ft 874.00 0.00 9,393 0
Depth of Flow over Riser(1 ft min)5 1.00 ft 875.00 1.00 11,000 10,186
Depth of Flow over Emergency Spillway 0.50 ft 876.00 2.00 12,665 22,009
25 Yr Storm Freeboard(1 ft req'd)5 1.00 ft 877.00 3.00 14,386 35,525
878.00 4.00 16,162 50,790
Basin Configuration 879.00 5.00 17,996 67,861
Bottom Elevation 874.00 msl
Sediment Storage Elevation 876.50 msl
Riser Crest 876.50 msl
Emergency Spillway Crest 877.50 msl
Top of Berm 879.00 msl
Skimmer Outlet Basin Size Check
Desired Skimmer Drawdown Time(td)6 72 hrs Basin Surface Area Provided at Spillway Crest 13,526 sf
Desired Skimmer Drawdown Rate(Qd) 3,390 ft3/day Basin Storage Volume Provided Below Spillway Crest 28,555 cf
Skimmer Size 8.0 in
Head on Orifice(H)5 0.500 ft
Calculated Orifice Diameter' 1.441 in
Actual Orifice Diameter' 1.500 in
Actual Skimmer Drawdown Time' 66 hrs
Barrel
Riser Diameter(15 in min)5 72 in Riser Flow as Weir13 58.43 cfs
Barrel Diameter' DOUBLE 24 in Riser Flow as Orifice14 136.14 cfs
Barrel Invert Elevation 874.00 msl
Barrel Length 50.00 ft Barrel Flow as Orifice14 47.83 cfs
Barrel Manning's N10 0.025 Barrel Flow as Pipe15 38.46 cfs
Sharp Crested Weir Coefficient(C)11 3.1
Orifice Coefficient(C)12 0.6 Controlling Flow through Riser and Barrel Spillway 38.46 cfs
Spillway
Minimum Allowable Spillway Length16 20 ft Difference b/n 25 Yr Peak Flow and Riser/Barrel Flow -10.73 cfs
Broad Crested Weir Coefficient(C)17 2.80 Ell Design Spillway Length" 20 ft
Concrete
Length of Exposed Outlet Pipe 10 ft Buoyancy18 6371 Ibs
Concrete Anchor Width 7.5 ft Weight of Concrete Anchor 8156 Ibs
Concrete Anchor Length 7.5 ft
Concrete Anchor Thickness 1.00 ft Safety Factor19 1.3
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
Page 15 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,hftp://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.61-Sediment Basin of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
7.Skimmer orifice equatic I
D= V Qa/(2370*V H) (inches) (see note 5)
8.Actual skimmer orifice diameter is rounded to the nearest 1/4 inch.
9.Riser cross-sectional area is required to be more than 1.5 times the barrel cross-sectional area.
10.Use 0.025 for CMP and 0.013 for RCP.
11.3.1 for corrugated metal pipe risers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
12.0.6 for corrugated mortal nine ricers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
13.Weir equation: Q= CLH7 5 (see note 11)
14.Orifice equation: Q=CA(2gH)R5 (see note 12)
15.Pipe Flow equation: 2gh O5 *See
Q=a [1+Km+KPL
16.Minimum allowable emergency spillway length is 20 feet(see note 5).
17.2.80 is the maximum allowable coefficient per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
18.Weight of water displaced by riser and exposed outlet pipe.
19.Minimum safety factor is 1.1 per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
Page 16 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Riser Sediment Basin: SB-209-Phase 1
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)1 6.40 ac 10 Yr Peak Flow(Q10) 27.88 cfs
Disturbed area(DA) 6.40 ac 25 Yr Peak Flow(Q25) 31.41 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 13,664 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (1800 cf per ac of TDA)5 11,520 cf
10 Yr Storm Rainfall Intensity(i)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)4 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 824.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 1.50 ft 824.00 0.00 11,576 0
Depth of Flow over Riser(1 ft min)5 1.00 ft 825.00 1.00 13,138 12,349
Depth of Flow over Emergency Spillway 0.50 ft 826.00 2.00 14,757 26,288
25 Yr Storm Freeboard(1 ft req'd)5 1.00 ft 827.00 3.00 16,432 41,875
828.00 4.00 18,164 59,166
Basin Configuration
Bottom Elevation 824.00 msl
Sediment Storage Elevation 825.50 msl
Riser Crest 825.50 msl
Emergency Spillway Crest 826.50 msl
Top of Berm 828.00 msl
Skimmer Outlet Basin Size Check
Desired Skimmer Drawdown Time(td)6 72 hrs Basin Surface Area Provided at Spillway Crest 13,948 sf
Desired Skimmer Drawdown Rate(Qd) 3,840 ft3/day Basin Storage Volume Provided Below Spillway Crest 19,119 cf
Skimmer Size 8.0 in
Head on Orifice(H)5 0.500 ft
Calculated Orifice Diameter' 1.533 in
Actual Orifice Diameter' 1.500 in
Actual Skimmer Drawdown Time' 75 hrs
Barrel
Riser Diameter(15 in min)5 60 in Riser Flow as Weir13 48.69 cfs
Barrel Diameter' 30 in Riser Flow as Orifice14 94.54 cfs
Barrel Invert Elevation 822.00 msl
Barrel Length 50.00 ft Barrel Flow as Orifice14 42.61 cfs
Barrel Manning's N10 0.025 Barrel Flow as Pipe15 36.89 cfs
Sharp Crested Weir Coefficient(C)11 3.1
Orifice Coefficient(C)12 0.6 Controlling Flow through Riser and Barrel Spillway 36.89 cfs
Spillway
Minimum Allowable Spillway Length16 20 ft Difference b/n 25 Yr Peak Flow and Riser/Barrel Flow -5.48 cfs
Broad Crested Weir Coefficient(C)17 2.80 Ell Design Spillway Length" 20 ft
Concrete
Length of Exposed Outlet Pipe 10 ft Buoyancy18 4901 Ibs
Concrete Anchor Width 7.5 ft Weight of Concrete Anchor 8156 Ibs
Concrete Anchor Length 7.5 ft
Concrete Anchor Thickness 1.00 ft Safety Factor19 1.7
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
Page 17 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,hftp://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.61-Sediment Basin of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
7.Skimmer orifice equatic I
D= V Qa/(2370*V H) (inches) (see note 5)
8.Actual skimmer orifice diameter is rounded to the nearest 1/4 inch.
9.Riser cross-sectional area is required to be more than 1.5 times the barrel cross-sectional area.
10.Use 0.025 for CMP and 0.013 for RCP.
11.3.1 for corrugated metal pipe risers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
12.0.6 for corrugated mortal nine ricers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
13.Weir equation: Q= CLH7 5 (see note 11)
14.Orifice equation: Q=CA(2gH)R5 (see note 12)
15.Pipe Flow equation: 2gh O5 *See
Q=a [1+Km+KPL
16.Minimum allowable emergency spillway length is 20 feet(see note 5).
17.2.80 is the maximum allowable coefficient per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
18.Weight of water displaced by riser and exposed outlet pipe.
19.Minimum safety factor is 1.1 per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
Page 18 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Riser Sediment Basin: SB-210-Phase 1
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)1 10.65 ac 10 Yr Peak Flow(Q10) 46.39 cfs
Disturbed area(DA) 6.00 ac 25 Yr Peak Flow(Q25) 52.27 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 22,738 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (1800 cf per ac of TDA)5 19,170 cf
10 Yr Storm Rainfall Intensity(i)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)4 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 880.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.50 ft 880.00 0.00 20,173 0
Depth of Flow over Riser(1 ft min)5 1.00 ft 881.00 1.00 22,098 21,128
Depth of Flow over Emergency Spillway 0.50 ft 882.00 2.00 24,079 44,210
25 Yr Storm Freeboard(1 ft req'd)5 1.00 ft 883.00 3.00 26,116 69,300
884.00 4.00 28,211 96,457
Basin Configuration 885.00 5.00 30,326 125,719
Bottom Elevation 880.00 msl
Sediment Storage Elevation 882.50 msl
Riser Crest 882.50 msl
Emergency Spillway Crest 883.50 msl
Top of Berm 885.00 msl
Skimmer Outlet Basin Size Check
Desired Skimmer Drawdown Time(td)6 72 hrs Basin Surface Area Provided at Spillway Crest 25,098 sf
Desired Skimmer Drawdown Rate(Qd) 6,390 ft3/day 113asin Storage Volume Provided Below Spillway Crest 56,503 cf
Skimmer Size 8.0 in
Head on Orifice(H)5 0.500 ft
Calculated Orifice Diameter' 1.978 in
Actual Orifice Diameter' 2.000 in
Actual Skimmer Drawdown Time' 70 hrs
Barrel
Riser Diameter(15 in min)5 72 in Riser Flow as Weir13 58.43 cfs
Barrel Diameter' DOUBLE 24 in Riser Flow as Orifice14 136.14 cfs
Barrel Invert Elevation 879.50 msl
Barrel Length 30.00 ft Barrel Flow as Orifice14 52.40 cfs
Barrel Manning's N10 0.025 Barrel Flow as Pipe15 47.52 cfs
Sharp Crested Weir Coefficient(C)11 3.1
Orifice Coefficient(C)12 0.6 Controlling Flow through Riser and Barrel Spillway 47.52 cfs
Spillway
Minimum Allowable Spillway Length16 20 ft Difference b/n 25 Yr Peak Flow and Riser/Barrel Flow 4.75 cfs
Broad Crested Weir Coefficient(C)17 2.80 Ell Design Spillway Length13 20 ft
Concrete
Length of Exposed Outlet Pipe 10 ft Buoyancy18 6371 Ibs
Concrete Anchor Width 7.0 ft Weight of Concrete Anchor 10658 Ibs
Concrete Anchor Length 7.0 ft
Concrete Anchor Thickness 1.50 ft Safety Factor19 1.7
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
Page 19 of 44

RISER SEDIMENT BASIN CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,hftp://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.61-Sediment Basin of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
7.Skimmer orifice equatic I
D= V Qa/(2370*V H) (inches) (see note 5)
8.Actual skimmer orifice diameter is rounded to the nearest 1/4 inch.
9.Riser cross-sectional area is required to be more than 1.5 times the barrel cross-sectional area.
10.Use 0.025 for CMP and 0.013 for RCP.
11.3.1 for corrugated metal pipe risers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
12.0.6 for corrugated mortal nine ricers per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
13.Weir equation: Q= CLH7 5 (see note 11)
14.Orifice equation: Q=CA(2gH)R5 (see note 12)
15.Pipe Flow equation: 2gh O5 *See
Q=a [1+Km+KPL
16.Minimum allowable emergency spillway length is 20 feet(see note 5).
17.2.80 is the maximum allowable coefficient per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
18.Weight of water displaced by riser and exposed outlet pipe.
19.Minimum safety factor is 1.1 per Section 8.07-Sediment Basin Design of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
Page 20 of 44

PLC Lithium Hydroxide Conversion Plant ���
Appendices
Appendix H — Sediment Trap
Calculations

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-222
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 0.50 ac 10 Yr Peak Flow(Q10) 2.18 cfs
Disturbed area(DA) 0.50 ac 25 Yr Peak Flow(Q25) 2.45 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 1,067 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 1,800 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 891.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 891.00 0.00 852 0
892.00 1.00 1,091 969
893.00 2.00 1,355 2,190
894.00 3.00 1,645 3,687
895.00 4.00 1,960 5,488
Basin Configuration
Bottom Elevation 891.00 msl
Sediment Storage Elevation 893.00 msl
Emergency Spillway Crest 894.00 msl
Top of Berm 895.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 1,355 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 2,190 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 21 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-223
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 0.40 ac 10 Yr Peak Flow(Q10) 1.74 cfs
Disturbed area(DA) 0.40 ac 25 Yr Peak Flow(Q25) 1.96 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 854 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 1,440 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 883.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 883.00 0.00 642 0
884.00 1.00 853 745
885.00 2.00 1,088 1,713
886.00 3.00 1,349 2,929
887.00 4.00 1,635 4,419
Basin Configuration
Bottom Elevation 883.00 msl
Sediment Storage Elevation 885.00 msl
Emergency Spillway Crest 886.00 msl
Top of Berm 887.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 1,088 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 1,713 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 22 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-224-Phase 2
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 1.55 ac 10 Yr Peak Flow(Q10) 6.75 cfs
Disturbed area(DA) 0.65 ac 25 Yr Peak Flow(Q25) 7.61 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 3,309 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 5,580 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 878.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 878.00 0.00 2,203 0
879.00 1.00 2,800 2,496
880.00 2.00 3,405 5,593
881.00 3.00 4,090 9,335
882.00 4.00 4,832 13,791
Basin Configuration
Bottom Elevation 878.00 msl
Sediment Storage Elevation 880.00 msl
Emergency Spillway Crest 881.00 msl
Top of Berm 882.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 3,405 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 5,593 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 23 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-225-Phase 1
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 2.58 ac 10 Yr Peak Flow(Q10) 11.24 cfs
Disturbed area(DA) 2.58 ac 25 Yr Peak Flow(Q25) 12.66 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 5,508 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 9,288 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 874.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 874.00 0.00 4,724 0
875.00 1.00 5,322 5,020
876.00 2.00 6,071 10,712
877.00 3.00 6,611 17,052
878.00 4.00 7,302 24,005
Basin Configuration
Bottom Elevation 874.00 msl
Sediment Storage Elevation 876.00 msl
Emergency Spillway Crest 877.00 msl
Top of Berm 878.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 6,071 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 10,712 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 24 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-225-Phase 2
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 1.66 ac 10 Yr Peak Flow(Q10) 7.23 cfs
Disturbed area(DA) 1.66 ac 25 Yr Peak Flow(Q25) 8.15 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 3,544 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 5,976 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 878.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 878.00 0.00 2,483 0
879.00 1.00 3,083 2,778
880.00 2.00 3,740 6,184
881.00 3.00 4,454 10,276
882.00 4.00 5,224 15,110
Basin Configuration
Bottom Elevation 878.00 msl
Sediment Storage Elevation 880.00 msl
Emergency Spillway Crest 881.00 msl
Top of Berm 882.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 3,740 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 6,184 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 25 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-226-Phase 2
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 1.50 ac 10 Yr Peak Flow(Q10) 6.53 cfs
Disturbed area(DA) 1.50 ac 25 Yr Peak Flow(Q25) 7.36 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 3,202 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 5,400 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 836.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 836.00 0.00 2,483 0
837.00 1.00 2,877 2,678
838.00 2.00 3,296 5,762
839.00 3.00 3,740 9,277
840.00 4.00 4,210 13,250
Basin Configuration
Bottom Elevation 836.00 msl
Sediment Storage Elevation 838.00 msl
Emergency Spillway Crest 839.00 msl
Top of Berm 840.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 3,296 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 5,762 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 26 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-227
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 0.70 ac 10 Yr Peak Flow(Q10) 3.05 cfs
Disturbed area(DA) 0.70 ac 25 Yr Peak Flow(Q25) 3.44 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 1,494 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 2,520 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 876.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 876.00 0.00 1,081 0
877.00 1.00 1,348 1,212
878.00 2.00 1,640 2,704
879.00 3.00 1,957 4,500
880.00 4.00 2,300 6,626
Basin Configuration
Bottom Elevation 876.00 msl
Sediment Storage Elevation 878.00 msl
Emergency Spillway Crest 879.00 msl
Top of Berm 880.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 1,640 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 2,704 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 27 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-228
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 0.80 ac 10 Yr Peak Flow(Q10) 3.48 cfs
Disturbed area(DA) 0.80 ac 25 Yr Peak Flow(Q25) 3.93 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 1,708 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 2,880 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 882.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 882.00 0.00 1,219 0
883.00 1.00 1,501 1,358
884.00 2.00 1,808 3,010
885.00 3.00 2,141 4,982
886.00 4.00 2,498 7,299
Basin Configuration
Bottom Elevation 882.00 msl
Sediment Storage Elevation 884.00 msl
Emergency Spillway Crest 885.00 msl
Top of Berm 886.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 1,808 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 3,010 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 28 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-229-Phase 1
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 1.99 ac 10 Yr Peak Flow(Q10) 8.67 cfs
Disturbed area(DA) 1.99 ac 25 Yr Peak Flow(Q25) 9.77 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 4,249 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 7,164 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 874.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 874.00 0.00 3,083 0
875.00 1.00 3,740 3,406
876.00 2.00 4,454 7,498
877.00 3.00 5,224 12,332
878.00 4.00 6,051 17,964
Basin Configuration
Bottom Elevation 874.00 msl
Sediment Storage Elevation 876.00 msl
Emergency Spillway Crest 877.00 msl
Top of Berm 878.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 4,454 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 7,498 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 29 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-229-Phase 2
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 1.50 ac 10 Yr Peak Flow(Q10) 6.53 cfs
Disturbed area(DA) 1.50 ac 25 Yr Peak Flow(Q25) 7.36 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 3,202 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 5,400 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 874.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 874.00 0.00 2,483 0
875.00 1.00 2,877 2,678
876.00 2.00 3,296 5,762
877.00 3.00 3,740 9,277
878.00 4.00 4,210 13,250
Basin Configuration
Bottom Elevation 874.00 msl
Sediment Storage Elevation 876.00 msl
Emergency Spillway Crest 877.00 msl
Top of Berm 878.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 3,296 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 5,762 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 30 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-230
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 2.25 ac 10 Yr Peak Flow(Q10) 9.80 cfs
Disturbed area(DA) 2.25 ac 25 Yr Peak Flow(Q25) 11.04 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 4,804 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 8,100 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 841.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 841.00 0.00 3,827 0
842.00 1.00 4,312 4,067
843.00 2.00 4,821 8,631
844.00 3.00 5,356 13,717
845.00 4.00 5,916 19,351
Basin Configuration
Bottom Elevation 841.00 msl
Sediment Storage Elevation 843.00 msl
Emergency Spillway Crest 844.00 msl
Top of Berm 845.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 4,821 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 8,631 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 31 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-231
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 0.60 ac 10 Yr Peak Flow(Q10) 2.61 cfs
Disturbed area(DA) 0.60 ac 25 Yr Peak Flow(Q25) 2.94 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 1,281 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 2,160 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 819.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 819.00 0.00 1,081 0
820.00 1.00 1,348 1,212
821.00 2.00 1,640 2,704
822.00 3.00 1,957 4,500
823.00 4.00 2,300 6,626
Basin Configuration
Bottom Elevation 819.00 msl
Sediment Storage Elevation 821.00 msl
Emergency Spillway Crest 822.00 msl
Top of Berm 823.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 1,640 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 2,704 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 32 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-232
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 0.80 ac 10 Yr Peak Flow(Q10) 3.48 cfs
Disturbed area(DA) 0.80 ac 25 Yr Peak Flow(Q25) 3.93 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 1,708 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 2,880 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 812.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 812.00 0.00 1,219 0
813.00 1.00 1,501 1,358
814.00 2.00 1,808 3,010
815.00 3.00 2,141 4,982
816.00 4.00 2,498 7,299
Basin Configuration
Bottom Elevation 812.00 msl
Sediment Storage Elevation 814.00 msl
Emergency Spillway Crest 815.00 msl
Top of Berm 816.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 1,808 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 3,010 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 33 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST233-Phase 1
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 3.10 ac 10 Yr Peak Flow(Q10) 13.50 cfs
Disturbed area(DA) 3.10 ac 25 Yr Peak Flow(Q25) 15.21 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 6,618 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 11,160 cf
10 Yr Storm Rainfall Intensity(i)° 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 840.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 840.00 0.00 5,600 0
841.00 1.00 6,300 5,947
842.00 2.00 7,059 12,622
843.00 3.00 7,800 20,049
844.00 4.00 8,660 28,275
Basin Configuration
Bottom Elevation 840.00 msl
Sediment Storage Elevation 842.00 msl
Emergency Spillway Crest 843.00 msl
Top of Berm 844.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 7,059 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 12,622 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 34 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-233-Phase 2
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 1.15 ac 10 Yr Peak Flow(Q10) 5.01 cfs
Disturbed area(DA) 1.15 ac 25 Yr Peak Flow(Q25) 5.64 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 2,455 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 4,140 cf
10 Yr Storm Rainfall Intensity i° 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 840.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 840.00 0.00 1,943 0
841.00 1.00 2,294 2,116
842.00 2.00 2,670 4,596
843.00 3.00 3,071 7,464
844.00 4.00 3,497 10,746
Basin Configuration
Bottom Elevation 840.00 msl
Sediment Storage Elevation 842.00 msl
Emergency Spillway Crest 843.00 msl
Top of Berm 844.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 2,670 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 4,596 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 35 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-234
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 0.50 ac 10 Yr Peak Flow(Q10) 2.18 cfs
Disturbed area(DA) 0.50 ac 25 Yr Peak Flow(Q25) 2.45 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 1,067 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 1,800 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 820.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 820.00 0.00 1,081 0
821.00 1.00 1,348 1,212
822.00 2.00 1,640 2,704
823.00 3.00 1,957 4,500
824.00 4.00 2,300 6,626
Basin Configuration
Bottom Elevation 820.00 msl
Sediment Storage Elevation 822.00 msl
Emergency Spillway Crest 823.00 msl
Top of Berm 824.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 1,640 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 2,704 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 36 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST-235
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 0.25 ac 10 Yr Peak Flow(Q10) 1.09 cfs
Disturbed area(DA) 0.25 ac 25 Yr Peak Flow(Q25) 1.23 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 534 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 900 cf
10 Yr Storm Rainfall Intensity(i)° 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 820.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 820.00 0.00 300 0
821.00 1.00 446 371
822.00 2.00 621 902
823.00 3.00 821 1,620
824.00 4.00 1,046 2,552
Basin Configuration
Bottom Elevation 820.00 msl
Sediment Storage Elevation 822.00 msl
Emergency Spillway Crest 823.00 msl
Top of Berm 824.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 621 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 902 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 37 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST236-Phase 1
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 2.80 ac 10 Yr Peak Flow(Q10) 12.20 cfs
Disturbed area(DA) 2.10 ac 25 Yr Peak Flow(Q25) 13.74 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 5,978 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 10,080 cf
10 Yr Storm Rainfall Intensity(i)° 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 877.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 877.00 0.00 4,724 0
878.00 1.00 5,322 5,020
879.00 2.00 6,071 10,712
880.00 3.00 6,611 17,052
881.00 4.00 7,302 24,005
Basin Configuration
Bottom Elevation 877.00 msl
Sediment Storage Elevation 879.00 msl
Emergency Spillway Crest 880.00 msl
Top of Berm 881.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 6,071 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 10,712 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 38 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST237-Phase 1
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 1.60 ac 10 Yr Peak Flow(Q10) 6.97 cfs
Disturbed area(DA) 1.50 ac 25 Yr Peak Flow(Q25) 7.85 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 3,416 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 5,760 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 888.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 888.00 0.00 3,069 0
889.00 1.00 3,505 3,285
890.00 2.00 3,966 7,018
891.00 3.00 4,453 11,225
892.00 4.00 4,964 15,931
Basin Configuration
Bottom Elevation 888.00 msl
Sediment Storage Elevation 890.00 msl
Emergency Spillway Crest 891.00 msl
Top of Berm 892.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 3,966 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 7,018 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 39 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST238-Phase 1
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 0.50 ac 10 Yr Peak Flow(Q10) 2.18 cfs
Disturbed area(DA) 0.50 ac 25 Yr Peak Flow(Q25) 2.45 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 1,067 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 1,800 cf
10 Yr Storm Rainfall Intensity(1)4 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 892.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 892.00 0.00 722 0
893.00 1.00 859 790
894.00 2.00 1,224 1,826
895.00 3.00 1,517 3,194
896.00 4.00 1,839 4,869
Basin Configuration
Bottom Elevation 892.00 msl
Sediment Storage Elevation 894.00 msl
Emergency Spillway Crest 895.00 msl
Top of Berm 896.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 1,224 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 1,826 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 40 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST239-Phase 1
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 3.20 ac 10 Yr Peak Flow(Q10) 13.94 cfs
Disturbed area(DA) 2.05 ac 25 Yr Peak Flow(Q25) 15.71 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 6,832 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 11,520 cf
10 Yr Storm Rainfall Intensity(i)° 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 856.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 856.00 0.00 5,603 0
857.00 1.00 6,313 5,954
858.00 2.00 7,059 12,637
859.00 3.00 7,842 20,084
860.00 4.00 8,662 28,333
Basin Configuration
Bottom Elevation 856.00 msl
Sediment Storage Elevation 858.00 msl
Emergency Spillway Crest 859.00 msl
Top of Berm 860.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 7,059 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 12,637 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 41 of 44

SEDIMENT TRAP CALCULATIONS
Lithium Hydroxide Conversion Plant
HDR PROJECT NO.: 10302238
DATE: 08.27.2021 BY: AKL
REVISED: 12.03.2021 RVW: VH
Sediment Trap: ST240-Phase 1
Drainage Area Characteristics Required Storage Volume
Total drainage area(TDA)' 2.95 ac 10 Yr Peak Flow(Q10) 12.85 cfs
Disturbed area(DA) 2.95 ac 25 Yr Peak Flow(Q25) 14.48 cfs
Rational Coefficient(C)2 0.60 Req'd Min.Surface Area (435 sf per cfs of Q25)5 6,298 sf
Time of Concentration(TC)3 5.0 min Req'd Min.Storage Volume (3600 cf per ac of TDA)5 10,620 cf
10 Yr Storm Rainfall Intensity(i)° 7.3 in/hr
25 Yr Storm Rainfall Intensity(i)° 8.2 in/hr
Design Criteria Basin Size
Bottom Elevation 870.00 msl Elev.(msl) Depth(ft) Area(sf) Cumulative Volume(cf)
Depth of Storage Volume 2.00 ft 870.00 0.00 5,600 0
871.00 1.00 6,300 5,947
872.00 2.00 7,059 12,622
873.00 3.00 7,800 20,049
874.00 4.00 8,660 28,275
Basin Configuration
Bottom Elevation 870.00 msl
Sediment Storage Elevation 872.00 msl
Emergency Spillway Crest 873.00 msl
Top of Berm 874.50 msl
Spillway Length Basin Size Check
Drainage Area Length of Spillway Basin Surface Area Provided at Spillway Crest 7,059 sf
1 4 Basin Storage Volume Provided Below Spillway Crest 12,622 cf
2 6
3 8
4 10
5 12
Notes
1.See attached drainage area map.
2.Entire area is denuded.Conservative rational coefficient for smooth bare packed soil is 0.60.
3.Time of concentration was assumed to be the minimum of 5 minutes.
4.Rainfall intensity at project location was acquired from the NOAA website,http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html.
5.From Section 6.60-Sediment Trap of the NCDEQ Erosion and Sediment Control Planning and Design Manual.
6.Basin is required to be dewatered by the skimmer in 48 to 120 hours.The optimal dewatering time is 72 hours(see note 5).
13.Weir equation: 0= CLH'5
Page 42 of 44

PLC Lithium Hydroxide Conversion Plant ���
Appendices
Appendix I —Stormwater
Calculations

CB v SB-5(North) SA-1 North (North) (North) 24"PIPE
5-N 5P 5R (North) SA-1 North SA-1 North
24"PIPE SB-5(North) SB-5(North) c6
1 B-S 1 B-R 1 B-P 1 B-N
4A-S SB-1(South) SB-1(South) SB-1(South) 24"PIPE
SB-4torth)
4A-N 4A-R 2-S 2-R 2-P 2-N
24"PIPE SB-4(North) SB-4(North) SB-2 SB-2 SB-2 24"PIPE
4B-N 4B-R
24"PIPE SB-4(South) SB-4 outh)
3-N
SB-3 SB-3 8B-3 18"PIPE
4B-S
SB-4(South)
Subcat Reach On Link Routing Diagram for Piedmont Ditches and Storm Sewer
Prepared by HDR, Inc, Printed 8/27/2021
HydroCAD®10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 2
Time span=0.00-2.00 hrs, dt=0.01 hrs, 201 points
Runoff by Rational method, Rise/Fall=1.0/1.0 xTc
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment1A-S:SA-1 (North) Runoff Area=2.926 ac 94.53% Impervious Runoff Depth=0.76"
Tc=0.0 min C=0.91 Runoff=20.49 cfs 0.186 of
Subcatchment1 B-S: SB-1 (South) Runoff Area=1.881 ac 96.28% Impervious Runoff Depth=0.77"
Tc=0.0 min C=0.92 Runoff=13.31 cfs 0.121 of
Subcatchment2-S: SIB-2 Runoff Area=3.607 ac 93.76% Impervious Runoff Depth=0.76"
Tc=0.0 min C=0.91 Runoff=25.25 cfs 0.230 of
Subcatchment3-S: SIB-3 Runoff Area=1.632 ac 87.25% Impervious Runoff Depth=0.72"
Tc=0.0 min C=0.86 Runoff=10.80 cfs 0.098 of
Subcatchment4A-S:SB-4(North) Runoff Area=3.076 ac 92.98% Impervious Runoff Depth=0.76"
Tc=0.0 min C=0.90 Runoff=21.30 cfs 0.194 of
Subcatchment4B-S: SB-4(South) Runoff Area=2.907 ac 89.85% Impervious Runoff Depth=0.74"
Tc=0.0 min C=0.88 Runoff=19.68 cfs 0.179 of
Subcatchment5S: SB-5(North) Runoff Area=2.907 ac 89.85% Impervious Runoff Depth=0.74"
Tc=0.0 min C=0.88 Runoff=19.68 cfs 0.179 of
Reach 1A-N:24" PIPE Avg. Flow Depth=1.37' Max Vet=8.69 fps Inflow=20.37 cfs 0.178 of
24.0" Round Pipe n=0.012 L=269.0' S=0.0100 '/' Capacity=24.51 cfs Outflow=19.85 cfs 0.178 of
Reach 1A-R:SA-1 (North) Avg. Flow Depth=1.11' Max Vet=4.21 fps Inflow=20.49 cfs 0.186 of
n=0.025 L=466.6' S=0.0100 '/' Capacity=84.58 cfs Outflow=20.37 cfs 0.178 of
Reach 1 B-N: 24" PIPE Avg. Flow Depth=1.05' Max Vet=7.96 fps Inflow=13.31 cfs 0.116 of
24.0" Round Pipe n=0.012 L=269.0' S=0.0100 '/' Capacity=24.51 cfs Outflow=13.29 cfs 0.116 of
Reach 1 B-R: SIB-1 (South) Avg. Flow Depth=0.93' Max Vet=3.79 fps Inflow=13.31 cfs 0.121 of
n=0.025 L=204.5' S=0.0100 '/' Capacity=84.53 cfs Outflow=13.31 cfs 0.116 of
Reach 2-N: 24" PIPE Avg. Flow Depth=1.61' Max Vet=8.89 fps Inflow=25.20 cfs 0.219 of
24.0" Round Pipe n=0.012 L=627.0' S=0.0100 '/' Capacity=24.51 cfs Outflow=24.01 cfs 0.219 of
Reach 2-R: SIB-2 Avg. Flow Depth=1.21' Max Vet=4.45 fps Inflow=25.25 cfs 0.230 of
n=0.025 L=407.0' S=0.0100 '/' Capacity=84.64 cfs Outflow=25.20 cfs 0.219 of
Reach 3-N: 18" PIPE Avg. Flow Depth=1.15' Max Vet=7.31 fps Inflow=10.80 cfs 0.094 of
18.0" Round Pipe n=0.012 L=627.0' S=0.0100 '/' Capacity=11.38 cfs Outflow=10.53 cfs 0.094 of
Reach 3-R: SIB-3 Avg. Flow Depth=0.61' Max Vet=6.22 fps Inflow=10.80 cfs 0.098 of
n=0.012 L=278.4' S=0.0100 '/' Capacity=176.20 cfs Outflow=10.80 cfs 0.094 of
Reach 4A-N:24" PIPE Avg. Flow Depth=1.35' Max Vet=8.66 fps Inflow=20.06 cfs 0.185 of
24.0" Round Pipe n=0.012 L=269.0' S=0.0100 '/' Capacity=24.51 cfs Outflow=19.48 cfs 0.185 of

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 3
Reach 4A-R:SB-4(North) Avg. Flow Depth=1.11' Max Vet=4.21 fps Inflow=21.30 cfs 0.194 of
n=0.025 L=627.0' S=0.0100 '/' Capacity=84.64 cfs Outflow=20.06 cfs 0.185 of
Reach 4B-N: 24" PIPE Avg. Flow Depth=1.33' Max Vet=8.63 fps Inflow=19.33 cfs 0.171 of
24.0" Round Pipe n=0.012 L=269.0' S=0.0100 '/' Capacity=24.51 cfs Outflow=19.10 cfs 0.171 of
Reach 4B-R: SIB-4(South) Avg. Flow Depth=1.09' Max Vet=4.18 fps Inflow=19.68 cfs 0.179 of
n=0.025 L=420.0' S=0.0100 '/' Capacity=84.64 cfs Outflow=19.33 cfs 0.171 of
Reach 5-N: 24" PIPE Avg. Flow Depth=1.34' Max Vet=8.64 fps Inflow=19.50 cfs 0.171 of
24.0" Round Pipe n=0.012 L=196.0' S=0.0100 '/' Capacity=24.51 cfs Outflow=19.18 cfs 0.171 of
Reach 5R: SB-5(North) Avg. Flow Depth=1.09' Max Vet=4.19 fps Inflow=19.68 cfs 0.179 of
n=0.025 L=400.0' S=0.0100 '/' Capacity=84.74 cfs Outflow=19.50 cfs 0.171 of
Pond 1A-P:SA-1 (North) Peak Elev=832.99' Inflow=20.37 cfs 0.178 of
24.0" Round Culvert n=0.012 L=269.0' S=0.0100 '/' Outflow=20.37 cfs 0.178 of
Pond 1 B-P: SB-1 (South) Peak Elev=831.95' Inflow=13.31 cfs 0.116 of
24.0" Round Culvert n=0.012 L=269.0' S=0.0100 '/' Outflow=13.31 cfs 0.116 of
Pond 2-P: SIB-2 Peak Elev=833.51' Inflow=25.20 cfs 0.219 of
24.0" Round Culvert n=0.012 L=269.0' S=0.0100 '/' Outflow=25.20 cfs 0.219 of
Pond 3-P: SIB-3 Peak Elev=833.39' Inflow=10.80 cfs 0.094 of
18.0" Round Culvert n=0.012 L=269.0' S=0.0100 '/' Outflow=10.80 cfs 0.094 of
Pond 4A-P:SB-4(North) Peak Elev=832.49' Inflow=20.06 cfs 0.185 of
24.0" Round Culvert n=0.012 L=269.0' S=0.0100 '/' Outflow=20.06 cfs 0.185 of
Pond 4B-P: SB-4(South) Peak Elev=832.36' Inflow=19.33 cfs 0.171 of
24.0" Round Culvert n=0.012 L=269.0' S=0.0100 '/' Outflow=19.33 cfs 0.171 of
Pond 5P: SB-5(North) Peak Elev=838.10' Inflow=19.50 cfs 0.171 of
24.0" Round Culvert n=0.012 L=196.0' S=0.0100 '/' Outflow=19.50 cfs 0.171 of
Total Runoff Area = 18.936 ac Runoff Volume = 1.187 of Average Runoff Depth = 0.75"
7.76% Pervious = 1.469 ac 92.24% Impervious = 17.467 ac

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 4
Summary for Subcatchment 1A-S: SA-1 (North)
Runoff = 20.49 cfs @ 0.00 hrs, Volume= 0.186 af, Depth= 0.76"
Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Gaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Area (ac) C Description
2.766 0.95
0.160 0.25
2.926 0.91 Weighted Average
0.160 5.47% Pervious Area
2.766 94.53% Impervious Area
Subcatchment 1A-S: SA-1 (North)
Hydrograph
22 - - - ■Runoff
20.49 cfs
20 - - - - -Gaston ACounty
18 - - - - - - -NG 23- Gar
17 - - - - - - - - - - -
16 - - - - - - - - - - -Duration=6Kmin-,
15 - 1 -
14 - -L - 1 I Lle n 7.6 a iMft
12 - fi :R-UX1off ACea*zm-aC
0 11 _R11r1D fY� =0. 6
FL: -
8 JhnoffDepth#G--7 "
7 - - - - - - - - TED.:Omin_
5 .-9
3 - - - -
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 5
Summary for Subcatchment 1 B-S: SB-1 (South)
Runoff = 13.31 cfs @ 0.00 hrs, Volume= 0.121 af, Depth= 0.77"
Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Gaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Area (ac) C Description
1.811 0.95
0.070 0.25
1.881 0.92 Weighted Average
0.070 3.72% Pervious Area
1.811 96.28% Impervious Area
Subcatchment 1 B-S: SBA (South)
Hydrograph
— — — — — — — — ■Runoff
13.31 cfs
13 - - - - - Gaston County
12 — — — — - NC25-Yeas
11
Duration=6 min-,
10 I
9 — — — — — — — — — — — lnten=7.63in/hr
8 T Runoff Area=1.881 ac
Runoff Volume=0.12-1-af
LL
6
- - - - - - - - - - Runoff Depth=0.77"
5
4 Tc=0.0 m i n
3 — - — — — C-0.92
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 6
Summary for Subcatchment 2-S: SB-2
Runoff = 25.25 cfs @ 0.00 hrs, Volume= 0.230 af, Depth= 0.76"
Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Gaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Area (ac) C Description
3.382 0.95
0.225 0.25
3.607 0.91 Weighted Average
0.225 6.24% Pervious Area
3.382 93.76% Impervious Area
Subcatchment 2-S: SB-2
Hydrograph
28 ■Runoff
25.25 cfs
24 -Gaswt7o/te L
n+moo u my
22 IYv �Year
20 Duration=6 min,
18
3 16 - - -ftnoff Area=3.607-ae
14
LL 12 ff
Ran-oVorurve=0.230 a#
101 Runoff: Depth=0.76"
T - - - - - - - - -Tc=O.Omin
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
6
4
2
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 7
Summary for Subcatchment 3-S: SB-3
Runoff = 10.80 cfs @ 0.00 hrs, Volume= 0.098 af, Depth= 0.72"
Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Gaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Area (ac) C Description
1.424 0.95
0.208 0.25
1.632 0.86 Weighted Average
0.208 12.75% Pervious Area
1.424 87.25% Impervious Area
Subcatchment 3-S: SB-3
Hydrograph
12 ❑Runoff
10.80 cfs
Gaston County
10 NC 25-Year
Duration=6 min,
Inten=7.63 in/hr
Runoff Area=1 .632 ac
° 6 Runoff Volume=0.098 of
LL 5
4
Runoff Depth=0.72"
Tc=0.0 m i n
3
2 C=0.86
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 8
Summary for Subcatchment 4A-S: SB-4 (North)
Runoff = 21.30 cfs @ 0.00 hrs, Volume= 0.194 af, Depth= 0.76"
Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Gaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Area (ac) C Description
2.860 0.95
0.216 0.25
3.076 0.90 Weighted Average
0.216 7.02% Pervious Area
2.860 92.98% Impervious Area
Subcatchment 4A-S: SB-4 (North)
Hydrograph
23 - - - - - - - - - - - - - - - - ■Runoff
21.30 cfs ,� �+
21 Gaston aston -Ounty
20
19 - - - - - - - - -NC25--Yeaip
18 -
17 - - - - - - -Duir'afian-6 mim
16 - - - - + - - - - - - -- - - - - - - - - -
15 - - - - - T - - - - - - fiMen--7.6arnf
14 13 - - - - - 1 - - -Runoff Area=10-7f-ac
12 - - - - - - L - - - - - - - -.„-�-,�- p- - - - -
o UL 11 T Ru-n-off�1{.1111C=V.194�
9 - - - - - - - - - —- - - FD- - - -7_ -
7 — - - - - - L - - - - - - - - - c---O
5 - fi �0�0
4
3
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 9
Summary for Subcatchment 4B-S: SB-4 (South)
Runoff = 19.68 cfs @ 0.00 hrs, Volume= 0.179 af, Depth= 0.74"
Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Gaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Area (ac) C Description
2.612 0.95
0.295 0.25
2.907 0.88 Weighted Average
0.295 10.15% Pervious Area
2.612 89.85% Impervious Area
Subcatchment 4B-S: SB-4 (South)
Hydrograph
22 - - - - - - - - - - - -
■Runoff
19.68 cfs
19 - 7G ston SOU-11ty
;$ - 1G25vear
15 16 - Duratlan-6 m�
T
14 T tfiten--7.6a in/111
v 12 -
3 11 p -Runoff l'�1.r„e,�aw=1n.7V -ac
2 10 - - 1 -Run-o fA1,oktFne=Q.4/�af
9 - - - - - -
-
8 - + - - - -RunofDeptb=Q74"
6 - - - - - - - - - - - -Tc=D!Omin
4 - - - - - - - - 0.88
3 - -
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 10
Summary for Subcatchment 5S: SB-5 (North)
Runoff = 19.68 cfs @ 0.00 hrs, Volume= 0.179 af, Depth= 0.74"
Runoff by Rational method, Rise/Fall=1.0/1.0 xTc, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Gaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Area (ac) C Description
2.612 0.95
0.295 0.25
2.907 0.88 Weighted Average
0.295 10.15% Pervious Area
2.612 89.85% Impervious Area
Subcatchment 5S: SB-5 (North)
Hydrograph
22 - - - - - - - - - - - -
■Runoff
19.68 cfs
19 - 7Gasfon :COunty
;$ - 1G25vear
15 16 - Duratlan=6 m�
T
14 T finten--7.6a in/111
v 12 -
3 11 -Runoff !Area=19 I -ac
2 10 - - L -Run-offA1,oktFne=0.479-af
9 - - - - - -
-
8 - + - - - -Runoff Deptb=Q74"
6 - - - - - - - - - - - -Tc=D!Omin
4 - - - - - - - - 0.88
3 - -
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 11
Summary for Reach 1A-N: 24" PIPE
Inflow Area = 2.926 ac, 94.53% Impervious, Inflow Depth = 0.73" for 25-Year event
Inflow = 20.37 cfs @ 0.13 hrs, Volume= 0.178 of
Outflow = 19.85 cfs @ 0.14 hrs, Volume= 0.178 af, Atten= 3%, Lag= 0.6 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 8.69 fps, Min. Travel Time= 0.5 min
Avg. Velocity = 1.65 fps, Avg. Travel Time= 2.7 min
Peak Storage= 617 cf @ 0.13 hrs INLET PIPE TO SB - 201
Average Depth at Peak Storage= 1.37' , Surface Width= 1.86' (Basin has double inlet pipes)
Bank-Full Depth= 2.00' Flow Area= 3.1 sf, Capacity= 24.51 cfs
24.0" Round Pipe
n= 0.012
Length= 269.0' Slope= 0.0100 '/'
Inlet Invert= 830.18', Outlet Invert= 827.49'
0
Reach 1A-N: 24" PIPE
Hydrograph
i - - - - - - - - - - - - - - - ■Inflow
22 / , 20.37 cfs — — — — — — — — — — — — — — — outflow
21 'Us
W-C
4nf low Area-�9-26 aE
20 //��
19 - - - - - - - - -Avg.-How-Depth--UT
18 - - - - - - - - - - - - -�- - ` - -
Q cA16
15 - -24-0n
w 13 - - Round Pipe
_o
LL 19 - - - - - - - - - - - - - -�nn26�9Q/r
5 - Z�PWftY-24.5'C cfS_
4 '
3
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 12
Summary for Reach 1A-R: SA-1 (North)
Inflow Area = 2.926 ac, 94.53% Impervious, Inflow Depth = 0.76" for 25-Year event
Inflow = 20.49 cfs @ 0.00 hrs, Volume= 0.186 of
Outflow = 20.37 cfs @ 0.13 hrs, Volume= 0.178 af, Atten= 1%, Lag= 7.5 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 4.21 fps, Min. Travel Time= 1.8 min
Avg. Velocity = 0.82 fps, Avg. Travel Time= 9.4 min
Peak Storage= 2,254 cf @ 0.10 hrs
Average Depth at Peak Storage= 1.11' , Surface Width= 7.68'
Bank-Full Depth= 2.00' Flow Area= 14.0 sf, Capacity= 84.58 cfs
1.00' x 2.00' deep channel, n= 0.025 Earth, clean &winding
Side Slope Z-value= 3.0 7' Top Width= 13.00'
Length= 466.6' Slope= 0.0100 '/'
Inlet Invert= 838.84', Outlet Invert= 834.18'
Reach 1A-R: SA-1 (North)
Hydrograph
■Inflow
22 20.49 cfs — — — — _ - — — — — — — — — — — — — — — — outflow
21 20.37df — — — — — — — - —� — — W10 w Tea--2.J26 ac
20 — — — — —� — — — — — — — — — — — — — L.
— —
19 — — — —
18 i — — — — — — — — — — — —� — — ���— — — — — — — — — — —
17 - - - - - - - - - - - - - - - - -Max_'M 4.21-fp
16 — — — — — —I — — — — — —
15 - - - - - - - - - - - - - - - - n=0.D25
14
13
12 — —� — — — — — — — — — — L��ks7�7�r
11
FL 10 - - - S=0.0100-T'
8
- -Gapadty=84:58 -ds
6 - — — —
5
4 - — —
3 -
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 13
Summary for Reach 1 B-N: 24" PIPE
Inflow Area = 1.881 ac, 96.28% Impervious, Inflow Depth = 0.74" for 25-Year event
Inflow = 13.31 cfs @ 0.11 hrs, Volume= 0.116 of
Outflow = 13.29 cfs @ 0.11 hrs, Volume= 0.116 af, Atten= 0%, Lag= 0.0 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 7.96 fps, Min. Travel Time= 0.6 min
Avg. Velocity = 1.75 fps, Avg. Travel Time= 2.6 min
INLET PIPE TO SB - 201
Peak Storage= 450 cf @ 0.11 hrs (Basin has double inlet pipes)
Average Depth at Peak Storage= 1.05' , Surface Width= 2.00'
Bank-Full Depth= 2.00' Flow Area= 3.1 sf, Capacity= 24.51 cfs
24.0" Round Pipe
n= 0.012
Length= 269.0' Slope= 0.0100 '/'
Inlet Invert= 830.18', Outlet Invert= 827.49'
0
Reach 1 B-N: 24" PIPE
Hydrograph
■Inflow
13.31 cfs ■outflow
14 13.29cN Inflow Area=1.881 ac
13 _ -Av(J•_FfowDe th=1_.05'
12 — —� — a p
11- - - - - - -UaxVel=7.96-fps
10
- - - - - - - - - - - - 2 .-0''-
N 9-
_ _ _ _ _ _ _Round Pipe
3 8
� "1— - - - - - - - - - - - n= 2
a
LL 6 - — - - - - - - - - - - -L=2690F
5 S=0.0100 T
4 - - -� - - - - apa�i#X=_24.5't cfs
3
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 14
Summary for Reach 1 B-R: S113-1 (South)
Inflow Area = 1.881 ac, 96.28% Impervious, Inflow Depth = 0.77" for 25-Year event
Inflow = 13.31 cfs @ 0.00 hrs, Volume= 0.121 of
Outflow = 13.31 cfs @ 0.11 hrs, Volume= 0.116 af, Atten= 0%, Lag= 6.6 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 3.79 fps, Min. Travel Time= 0.9 min
Avg. Velocity = 0.90 fps, Avg. Travel Time= 3.8 min
Peak Storage= 717 cf @ 0.10 hrs
Average Depth at Peak Storage= 0.93' , Surface Width= 6.56'
Bank-Full Depth= 2.00' Flow Area= 14.0 sf, Capacity= 84.53 cfs
1.00' x 2.00' deep channel, n= 0.025 Earth, clean &winding
Side Slope Z-value= 3.0 7' Top Width= 13.00'
Length= 204.5' Slope= 0.0100 '/'
Inlet Invert= 836.22', Outlet Invert= 834.18'
Reach 1 B-R: SBA (South)
Hydrograph
■Inflow
13.31 cfs 0 Outflow
14 1331cfs Inflow Area=1 .881 ac
13
12 - - - Avg.-low Depth=0.93'
11 — — — —Max_Ve]=_3-79_fps
10 I - - - - - - - - - - - - - - - x�0.025-
_ 9
N U $ L L —_2N.-5'
'LL - - - - - S=0.0t0_0_'/_
6
5 - - - - - - IC-apacity=84.53-cf
- - - - - - - - - - - - - - - -
3
2-
1-
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 15
Summary for Reach 2-N: 24" PIPE
Inflow Area = 3.607 ac, 93.76% Impervious, Inflow Depth = 0.73" for 25-Year event
Inflow = 25.20 cfs @ 0.12 hrs, Volume= 0.219 of
Outflow = 24.01 cfs @ 0.14 hrs, Volume= 0.219 af, Atten= 5%, Lag= 1.7 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 8.89 fps, Min. Travel Time= 1.2 min
Avg. Velocity = 1.73 fps, Avg. Travel Time= 6.0 min INLET PIPE TO
Peak Storage= 1,695 cf @ 0.12 hrs SIB - 202
Average Depth at Peak Storage= 1.61' , Surface Width= 1.59'
Bank-Full Depth= 2.00' Flow Area= 3.1 sf, Capacity= 24.51 cfs
24.0" Round Pipe
n= 0.012
Length= 627.0' Slope= 0.0100 '/'
Inlet Invert= 829.74', Outlet Invert= 823.47'
0
Reach 2-N: 24" PIPE
Hydrograph
❑I l nfow 28
25.20 cfs ❑Outflow
26 Inflow Area=3.607 ac
24.01 cfs
24 Avg. Flow Depth=1.61'
22 - - - - - - _ _ Max Vet=8.89 fps
20-
18 24.0"
y 16 Round Pipe
3 14 n=0.012
0
12 L=627.0'
10 S=0.0100 T
8
6 Capacity=24.51 cfs
4
2
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 16
Summary for Reach 2-R: S113-2
Inflow Area = 3.607 ac, 93.76% Impervious, Inflow Depth = 0.76" for 25-Year event
Inflow = 25.25 cfs @ 0.00 hrs, Volume= 0.230 of
Outflow = 25.20 cfs @ 0.12 hrs, Volume= 0.219 af, Atten= 0%, Lag= 6.9 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 4.45 fps, Min. Travel Time= 1.5 min
Avg. Velocity = 0.82 fps, Avg. Travel Time= 8.3 min
Peak Storage= 2,289 cf @ 0.10 hrs
Average Depth at Peak Storage= 1.21' , Surface Width= 8.28'
Bank-Full Depth= 2.00' Flow Area= 14.0 sf, Capacity= 84.64 cfs
1.00' x 2.00' deep channel, n= 0.025 Earth, clean &winding
Side Slope Z-value= 3.0 7' Top Width= 13.00'
Length= 407.0' Slope= 0.0100 '/'
Inlet Invert= 837.81', Outlet Invert= 833.74'
Reach 2-R: S113-2
Hydrograph
— — _ _ _ _ _ _ ■Inflow
28 25.25 cfs I❑Outflow
26 25.20df In#law-Area=3.607 ac
24 - _ _ _ _ _; _ Avg. Flow Depth=1.21'
22 — — — —
20 — — — — — — lulaXVel=4.-5fps
18 — — — — — — — — — — — — — — n=0.025
-, - - - - - -I — — — — — — — — — — — — — — — —
16 L=407.0'
3 14
1 VV
L—°° 12 — — —I — — — — — — — — C=0.0 'P
10 - - - - - -capacity=$4.64-c#s
8-
6-
4-
2
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 17
Summary for Reach 3-N: 18" PIPE
Inflow Area = 1.632 ac, 87.25% Impervious, Inflow Depth = 0.69" for 25-Year event
Inflow = 10.80 cfs @ 0.11 hrs, Volume= 0.094 of
Outflow = 10.53 cfs @ 0.13 hrs, Volume= 0.094 af, Atten= 2%, Lag= 1.2 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 7.31 fps, Min. Travel Time= 1.4 min
Avg. Velocity = 1.38 fps, Avg. Travel Time= 7.6 min
Peak Storage= 909 cf @ 0.11 hrs INLET PIPE TO
Average Depth at Peak Storage= 1.15' , Surface Width= 1.27' SIB - 203
Bank-Full Depth= 1.50' Flow Area= 1.8 sf, Capacity= 11.38 cfs
18.0" Round Pipe
n= 0.012
Length= 627.0' Slope= 0.0100 '/'
Inlet Invert= 831.03', Outlet Invert= 824.76'
0
Reach 3-N: 18" PIPE
Hydrograph
12 ❑I l nfow
10.80cf5 ❑Outflow
11 10.530, Inflow Area=1.632 ac
10 Avg. Flow Depth=1.15'
9 Max Vet=7.31 fps
18.0"
y Round Pipe
3 6 n=0.012
LL 5 L=627.0'
4 S=0.0100 T
3 Capacity=11.38 cfs
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 18
Summary for Reach 3-R: S113-3
Inflow Area = 1.632 ac, 87.25% Impervious, Inflow Depth = 0.72" for 25-Year event
Inflow = 10.80 cfs @ 0.00 hrs, Volume= 0.098 of
Outflow = 10.80 cfs @ 0.11 hrs, Volume= 0.094 af, Atten= 0%, Lag= 6.6 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 6.22 fps, Min. Travel Time= 0.7 min
Avg. Velocity = 1.88 fps, Avg. Travel Time= 2.5 min
Peak Storage= 483 cf @ 0.10 hrs
Average Depth at Peak Storage= 0.61' , Surface Width= 4.67'
Bank-Full Depth= 2.00' Flow Area= 14.0 sf, Capacity= 176.20 cfs
1.00' x 2.00' deep channel, n= 0.012
Side Slope Z-value= 3.0 7' Top Width= 13.00'
Length= 278.4' Slope= 0.0100 '/'
Inlet Invert= 837.81', Outlet Invert= 835.03'
Reach 3-R: S113-3
Hydrograph
■Inflow
12 10.80 ifs — — — — — — — — — — — — — — — ■Outflow
11 ' 10.80 cfs — — — — — - lnflowArea=a -682 ac
10 Avg. Flow Depth=0.61'
Max Vet=6.22 fps
- - - n=0.D12
L=278.4'
5 - S=0.0100 T
4 CapaciW-17-6-.20-efs-
3
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 19
Summary for Reach 4A-N: 24" PIPE
Inflow Area = 3.076 ac, 92.98% Impervious, Inflow Depth = 0.72" for 25-Year event
Inflow = 20.06 cfs @ 0.14 hrs, Volume= 0.185 of
Outflow = 19.48 cfs @ 0.15 hrs, Volume= 0.185 af, Atten= 3%, Lag= 0.7 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 8.66 fps, Min. Travel Time= 0.5 min
Avg. Velocity = 1.83 fps, Avg. Travel Time= 2.5 min
Peak Storage= 607 cf @ 0.14 hrs
Average Depth at Peak Storage= 1.35' , Surface Width= 1.87' INLET PIPE TO SB - 204
Bank-Full Depth= 2.00' Flow Area= 3.1 sf, Capacity= 24.51 cfs (Basin has double inlet pipes)
24.0" Round Pipe
n= 0.012
Length= 269.0' Slope= 0.0100 '/'
Inlet Invert= 829.73', Outlet Invert= 827.04'
C)
Reach 4A-N: 24" PIPE
Hydrograph
— — — — — — — — — — — — — — — — — — — — — — — — — — — — -
i — — — — — — — — — — — — — —I — — — — — — — — — — — — — — ■Inflow
22 i 20.06 cfs — — — — — — — — — — — — — — — — — — — — — — — — — — — ■Outflow
21 i
- - - - - - - - - - - - - - - - - inflow Area=1(f76 -ao
20 / 19.48 cfs — — — — — — — — — — — — — — — — — — — — — — — — — — — — — —
- - - - - - - - - - - - - - - - -A-v -Row-� th=4.3r
19 i pp-��
18 — — — — — — — — — — — — — — — — — — — — — — —- — — — —
17 — — — — — — — — — — — — — - - - - - -MaxAtel=8.66Af_ps
15 — — — — — — —� — — — — — — — — — —
14
y13 — — — — — — - - - - - - Round Pipe
u 12 — —� — — — — —
3 11 n=0-0a
10 i
LL 9 - - - - - - - - - - - -L=269.0'
8 - _ _ - - - - -S_0_01GO-�
5 - - - rapacity-_24.3'F ds
4
3
2-
0-
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 20
Summary for Reach 4A-R: S113-4 (North)
Inflow Area = 3.076 ac, 92.98% Impervious, Inflow Depth = 0.76" for 25-Year event
Inflow = 21.30 cfs @ 0.00 hrs, Volume= 0.194 of
Outflow = 20.06 cfs @ 0.14 hrs, Volume= 0.185 af, Atten= 6%, Lag= 8.2 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 4.21 fps, Min. Travel Time= 2.5 min
Avg. Velocity = 0.90 fps, Avg. Travel Time= 11.6 min
Peak Storage= 3,000 cf @ 0.10 hrs
Average Depth at Peak Storage= 1.11' , Surface Width= 7.64'
Bank-Full Depth= 2.00' Flow Area= 14.0 sf, Capacity= 84.64 cfs
1.00' x 2.00' deep channel, n= 0.025 Earth, clean &winding
Side Slope Z-value= 3.0 7' Top Width= 13.00'
Length= 627.0' Slope= 0.0100 '/'
Inlet Invert= 840.00', Outlet Invert= 833.73'
Reach 4A-R: S113-4 (North)
Hydrograph
—I — — — — — — — — — — — — — — — — ■Inflow
23 21.30 cfs _ — — — — — — — — — — — — — — — — — — — outflow
22 - - - - - - - - - - -I - - Inflow-Area=3-07Gae
21 20.06 cfs
20 - - Avg. Flaw Delith='r 11'
19 — — — — — — — — —
1$ - - - — — — — — —Mem—W=i&zijp
15 ' — - — — — — — — -n=0.02
14
13 — — — — — — — — L=V27.-0,
12 — — — — — — — — — — — — — — — — — A —/�— — —
LL 110 — — — — — — — — — — £-Q.00LOWT
s - j-alaa_c-lty_-U, C. s
6
5
4
3
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 21
Summary for Reach 4B-N: 24" PIPE
Inflow Area = 2.907 ac, 89.85% Impervious, Inflow Depth = 0.71" for 25-Year event
Inflow = 19.33 cfs @ 0.12 hrs, Volume= 0.171 of
Outflow = 19.10 cfs @ 0.13 hrs, Volume= 0.171 af, Atten= 1%, Lag= 0.7 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 8.63 fps, Min. Travel Time= 0.5 min
Avg. Velocity = 1.60 fps, Avg. Travel Time= 2.8 min
Peak Storage= 597 cf @ 0.12 hrs INLET PIPE TO SB - 204
Average Depth at Peak Storage= 1.33' , Surface Width= 1.89' (Basin has double inlet pipes)
Bank-Full Depth= 2.00' Flow Area= 3.1 sf, Capacity= 24.51 cfs
24.0" Round Pipe
n= 0.012
Length= 269.0' Slope= 0.0100 '/'
Inlet Invert= 829.73', Outlet Invert= 827.04'
0
Reach 4B-N: 24" PIPE
Hydrograph
— — — — — — — — — — — — — — — —I — — — — — — — — — — — — — — — —
■Inflow
21 19.33 cs — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — 0 outflow
20 19.10cs - - - - - - - - - - - - - — - - - 4nftoY TT ea=2-.9n7 -ac— — — — — — —I — — — — — — — — — — — —
18 Avg.-RowDept�=1.33'
17 — — — — — — — — — — — — — — — — — — — —
16 ' — — — — — — — — — — — — — — — — — — — —MaxyQl_=8.63fps
15 — — — — — — — — — — — — — — — — — 24.10W
14 — — — — — — —I — — — — — — — — — — — — — — —
13 — — — — — — — — — — — - - - - - - - - -RoundPipa
12 — — — — — — — — — — — —I — — — — — — — — — — — — —
311 — — — — — — — — — — — — — — — — — — — — — n--"12
0 10
LL 9 - - - - - - - - L-=269G-
8
7 - - - - - - - - - - - -S=0,01WI/'
6
5 - _apaci y=24.5'1_cfa
4
3
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 22
Summary for Reach 4113-R: S113-4 (South)
Inflow Area = 2.907 ac, 89.85% Impervious, Inflow Depth = 0.74" for 25-Year event
Inflow = 19.68 cfs @ 0.00 hrs, Volume= 0.179 of
Outflow = 19.33 cfs @ 0.12 hrs, Volume= 0.171 af, Atten= 2%, Lag= 7.1 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 4.18 fps, Min. Travel Time= 1.7 min
Avg. Velocity = 0.80 fps, Avg. Travel Time= 8.8 min
Peak Storage= 1,953 cf @ 0.10 hrs
Average Depth at Peak Storage= 1.09' , Surface Width= 7.54'
Bank-Full Depth= 2.00' Flow Area= 14.0 sf, Capacity= 84.64 cfs
1.00' x 2.00' deep channel, n= 0.025 Earth, clean &winding
Side Slope Z-value= 3.0 7' Top Width= 13.00'
Length= 420.0' Slope= 0.0100 '/'
Inlet Invert= 837.93', Outlet Invert= 833.73'
Reach 4113-R: S113-4 (South)
Hydrograph
- - -1 - - - - - - - - - - - - - - - -
■Inflow
21 19.68 cfs - - - - - - - - - - -I - - --jam-� -`-A,-�-rp- - - -7y1- - -^_ Outflow
20 19.33 cfs - - - - - - - - - - -I - - N FfID Y-Y-/-41 ea=2M7 ac
19 i - - - - - - - - - - -1 - - - - - - - - - -
18 , - - - - - -1 - Avg.-Flaw Depth=I-
17 - - - - - - - - - - - - -
16 - - - - -I - - - - -IWC�X VVCt�18-fpS
15
14 - - - -1 - - - - - - - - - - -n=e.025
13 - - -1 - - - - - - - - - - - - - - - -
tn
u 12 L=42 n�,
a 10 S=e.e 1 V V 'r
LL 7 j Capacity=&4.6`4_ds
7
6 I -
5 I 4-
3-
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 23
Summary for Reach 5-N: 24" PIPE
Inflow Area = 2.907 ac, 89.85% Impervious, Inflow Depth = 0.71" for 25-Year event
Inflow = 19.50 cfs @ 0.12 hrs, Volume= 0.171 of
Outflow = 19.18 cfs @ 0.12 hrs, Volume= 0.171 af, Atten= 2%, Lag= 0.5 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 8.64 fps, Min. Travel Time= 0.4 min
Avg. Velocity = 1.57 fps, Avg. Travel Time= 2.1 min
Peak Storage= 438 cf @ 0.12 hrs INLET PIPE TO
Average Depth at Peak Storage= 1.34' , Surface Width= 1.88' SB - 205
Bank-Full Depth= 2.00' Flow Area= 3.1 sf, Capacity= 24.51 cfs
24.0" Round Pipe
n= 0.012
Length= 196.0' Slope= 0.0100 T
Inlet Invert= 835.44', Outlet Invert= 833.48'
0
Reach 5-N: 24" PIPE
Hydrograph
/ — — — — — — — — - - — — — — — — — — — — — — — — ■Inflow
21 / 19.50 cfs - - - - `-., e p - �n - ■�UtfIOW
20 19.18 cfs - -� - - - ini{lo Y� Area=2.907 -ac
19 / — — —
18 / -� - - -vg._F1owD0ffi_1.34!
16 i - — — — — — IWAX- VQl=3.60p6-
_I _ _ _ _ _
-� — — — — — — —
14 — — — — — .�µ
13 -� - - - - - Round Pipe
12
;o - - - - - - - - - - - - n=0�12
.2 9 - - - L=19641
8
S=0-0a WIP
5 - - - _apaci y=24.5'1_cfs
4-
3-
2-
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 24
Summary for Reach 5R: S113-5 (North)
Inflow Area = 2.907 ac, 89.85% Impervious, Inflow Depth = 0.74" for 25-Year event
Inflow = 19.68 cfs @ 0.00 hrs, Volume= 0.179 of
Outflow = 19.50 cfs @ 0.12 hrs, Volume= 0.171 af, Atten= 1%, Lag= 7.0 min
Routing by Stor-Ind+Trans method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Max. Velocity= 4.19 fps, Min. Travel Time= 1.6 min
Avg. Velocity = 0.79 fps, Avg. Travel Time= 8.4 min
Peak Storage= 1,862 cf @ 0.10 hrs
Average Depth at Peak Storage= 1.09' , Surface Width= 7.54'
Bank-Full Depth= 2.00' Flow Area= 14.0 sf, Capacity= 84.74 cfs
1.00' x 2.00' deep channel, n= 0.025 Earth, clean &winding
Side Slope Z-value= 3.0 7' Top Width= 13.00'
Length= 400.0' Slope= 0.0100 '/'
Inlet Invert= 839.44', Outlet Invert= 835.43'
Reach 5R: S113-5 (North)
Hydrograph
- - -I - - - - - - - - - - - - - - - -
■Inflow
21 19.68 cfs — — — — — — — --j -2T —`—A,—�—rp— — 7—/1—TM— — —^— Outflow
20 19.50 cfs - — — — — — — H H I 0 Y-Y-/1-�Ga-2 rV�7 a V-
19 -
18 - - - - -I - Avg.-Flaw Depth=I-
17 i - - - - - - - - - - - -
16 - - - -I - - - - -Max V�Ct��9-fps
15
14 - - -I - - - - - - - - - - -n=e.025
13 - - - - - - - - - - - - - - - - - - -
tn
u 12 - -I - - L_4N.-O,
3 11
2 19 �7=e.OM 'P�
Capacity=&4.74_ds
6 5-
4-
3-
2-
1
0
0 1 Rol
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 25
Summary for Pond 1A-P: SA-1 (North)
Inflow Area = 2.926 ac, 94.53% Impervious, Inflow Depth = 0.73" for 25-Year event
Inflow = 20.37 cfs @ 0.13 hrs, Volume= 0.178 of
Outflow = 20.37 cfs @ 0.13 hrs, Volume= 0.178 af, Atten= 0%, Lag= 0.0 min
Primary = 20.37 cfs @ 0.13 hrs, Volume= 0.178 of
Routing by Stor-Ind method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Peak Elev= 832.99'@ 0.13 hrs
Device Routing Invert Outlet Devices
#1 Primary 830.18' 24.0" Round Culvert
L= 269.0' RCP, square edge headwall, Ke= 0.500
Inlet/ Outlet Invert= 830.18'/827.49' S= 0.0100 T Cc= 0.900
n= 0.012, Flow Area= 3.14 sf
Primary OutFlow Max=19.95 cfs @ 0.13 hrs HW=832.92' (Free Discharge)
L1=Culvert (Inlet Controls 19.95 cfs @ 6.35 fps)
Pond 1A-P: SA-1 (North)
Hydrograph
— — — — — — — — — — — — — — — —I — — — — — — — — — — — ❑ Inflow
22 20.37 its — — — — — — — — — — —I — — — — — — — ❑Primary
21 20.37 cfs — — — — — — — —I —Inflow Area=2.926 ac
20
18 - - - - - _ Peak Elev=832.99'
17 i
16 24.0"
15
14 Round Culvert
w 13
3 11 n=0.012
0
LL 19
L=269.0'
8
S=0.0100 T
6
5
4
3
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 26
Summary for Pond 1 B-P: SB-1 (South)
Inflow Area = 1.881 ac, 96.28% Impervious, Inflow Depth = 0.74" for 25-Year event
Inflow = 13.31 cfs @ 0.11 hrs, Volume= 0.116 of
Outflow = 13.31 cfs @ 0.11 hrs, Volume= 0.116 af, Atten= 0%, Lag= 0.0 min
Primary = 13.31 cfs @ 0.11 hrs, Volume= 0.116 of
Routing by Stor-Ind method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Peak Elev= 831.95' @ 0.11 hrs
Device Routing Invert Outlet Devices
#1 Primary 830.18' 24.0" Round Culvert
L= 269.0' RCP, square edge headwall, Ke= 0.500
Inlet/ Outlet Invert= 830.18'/ 827.49' S= 0.0100 '/' Cc= 0.900
n= 0.012, Flow Area= 3.14 sf
Primary OutFlow Max=13.31 cfs @ 0.11 hrs HW=831.95' (Free Discharge)
L1=Culvert (Inlet Controls 13.31 cfs @ 4.53 fps)
Pond 1 B-P: SBA (South)
Hydrograph
—I ❑ Inflow
13.31 cfs ❑Primary
14 13.31cfs _Inflow_Area= L.6&1_ac_
13
12 — — — — — — — — — — —PeakElev=831 .-W
11 — — — — — — — — — — — — — — — — — — — — —24.0"
10
- - Round Culvert
N
8 _ n=0-012-
0 7 — —, —
LL 6 L=269.0'
5 &-O—Q1D0 '/'_
4-
3-
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 27
Summary for Pond 2-P: SB-2
Inflow Area = 3.607 ac, 93.76% Impervious, Inflow Depth = 0.73" for 25-Year event
Inflow = 25.20 cfs @ 0.12 hrs, Volume= 0.219 of
Outflow = 25.20 cfs @ 0.12 hrs, Volume= 0.219 af, Atten= 0%, Lag= 0.0 min
Primary = 25.20 cfs @ 0.12 hrs, Volume= 0.219 of
Routing by Stor-Ind method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Peak Elev= 833.51' @ 0.12 hrs
Device Routing Invert Outlet Devices
#1 Primary 829.74' 24.0" Round Culvert
L= 269.0' RCP, square edge headwall, Ke= 0.500
Inlet/ Outlet Invert= 829.74'/ 827.05' S= 0.0100 '/' Cc= 0.900
n= 0.012, Flow Area= 3.14 sf
Primary OutFlow Max=24.90 cfs @ 0.12 hrs HW=833.45' (Free Discharge)
L1=Culvert (Inlet Controls 24.90 cfs @ 7.93 fps)
Pond 2-P: SB-2
Hydrograph
_ _
28 ❑ Inflow
� z5.zocrs — — — — — — — — — — — — — — — — — — — — ❑Primary
26 25.20 cfs - -I -Inflow area=3:60Tac
z2 _ _ _ -P-eak Elev=833.5a'
20 - - - - - - - - - - - - - 24.OWL
- -
- - - - - - - - - - - - Round Culvert
w 16-
3 14- — — — — — — — — — — — — — — — 1�— .0'��
0
LL 12- — — — — — — — — — — — — — — — — — — — - - - - -L-269.-Or
- - - - - - - - -II - - - -S---0-0-1001/1
-
6-
4-
2-
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 28
Summary for Pond 3-P: SB-3
Inflow Area = 1.632 ac, 87.25% Impervious, Inflow Depth = 0.69" for 25-Year event
Inflow = 10.80 cfs @ 0.11 hrs, Volume= 0.094 of
Outflow = 10.80 cfs @ 0.11 hrs, Volume= 0.094 af, Atten= 0%, Lag= 0.0 min
Primary = 10.80 cfs @ 0.11 hrs, Volume= 0.094 of
Routing by Stor-Ind method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Peak Elev= 833.39'@ 0.11 hrs
Device Routing Invert Outlet Devices
#1 Primary 831.03' 18.0" Round Culvert
L= 269.0' RCP, square edge headwall, Ke= 0.500
Inlet/ Outlet Invert= 831.03'/828.34' S= 0.0100 T Cc= 0.900
n= 0.012, Flow Area= 1.77 sf
Primary OutFlow Max=10.80 cfs @ 0.11 hrs HW=833.39' (Free Discharge)
L1=Culvert (Inlet Controls 10.80 cfs @ 6.11 fps)
Pond 3-P: SB-3
Hydrograph
I ❑ Inflow
12 10.80 cfs ❑Primary
11 10.80 cfs Inflow Area=1 .632 ac
10 Peak Elev=833.39'
9 18.0"
8
7
Round Culvert
N - — -
w
3 6 n=0.012
LL 5 L=269.0'
4 S=0.0100 T
3
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 29
Summary for Pond 4A-P: SB-4 (North)
Inflow Area = 3.076 ac, 92.98% Impervious, Inflow Depth = 0.72" for 25-Year event
Inflow = 20.06 cfs @ 0.14 hrs, Volume= 0.185 of
Outflow = 20.06 cfs @ 0.14 hrs, Volume= 0.185 af, Atten= 0%, Lag= 0.0 min
Primary = 20.06 cfs @ 0.14 hrs, Volume= 0.185 of
Routing by Stor-Ind method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Peak Elev= 832.49'@ 0.14 hrs
Device Routing Invert Outlet Devices
#1 Primary 829.73' 24.0" Round Culvert
L= 269.0' RCP, square edge headwall, Ke= 0.500
Inlet/ Outlet Invert= 829.73'/827.04' S= 0.0100 T Cc= 0.900
n= 0.012, Flow Area= 3.14 sf
Primary OutFlow Max=19.78 cfs @ 0.14 hrs HW=832.44' (Free Discharge)
L1=Culvert (Inlet Controls 19.78 cfs @ 6.30 fps)
Pond 4A-P: SB-4 (North)
Hydrograph
- - - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - - - - - - - - - - ❑ Inflow
22 120.06 cfs I - - - - - - - - - - - - - - - - - - - - - - - - -
❑Primary
20 2006ofs Inflow Area=3.076 ac
18 Peak Elev=832.49'
17 - - - - - - - - - - - -
- - 24.0"
16 - - - - - - - - - -
15 - - - - - - - - - -
14 , - - - - - - - - - - - -
' - Round Culvert
y 13 i - - - - - - - - - - - - - -I -
122/
g 11 ' i
a 10 - - - - - - - - - -
9 - - - - - - - - - - L=269.0
8 - - - - - - - -
- - - - - - - S=0.0100T
6 - - -
5 - - -
4
3
2
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 30
Summary for Pond 4B-P: SB-4 (South)
Inflow Area = 2.907 ac, 89.85% Impervious, Inflow Depth = 0.71" for 25-Year event
Inflow = 19.33 cfs @ 0.12 hrs, Volume= 0.171 of
Outflow = 19.33 cfs @ 0.12 hrs, Volume= 0.171 af, Atten= 0%, Lag= 0.0 min
Primary = 19.33 cfs @ 0.12 hrs, Volume= 0.171 of
Routing by Stor-Ind method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Peak Elev= 832.36' @ 0.12 hrs
Device Routing Invert Outlet Devices
#1 Primary 829.73' 24.0" Round Culvert
L= 269.0' RCP, square edge headwall, Ke= 0.500
Inlet/ Outlet Invert= 829.73'/ 827.04' S= 0.0100 '/' Cc= 0.900
n= 0.012, Flow Area= 3.14 sf
Primary OutFlow Max=19.25 cfs @ 0.12 hrs HW=832.35' (Free Discharge)
L1=Culvert (Inlet Controls 19.25 cfs @ 6.13 fps)
Pond 4B-P: SB-4 (South)
Hydrograph
— — — — — —I — — - — — — — — — — — — — ❑ Inflow
21 i 19.33 cfs — — — — — — — — — — — — — — — — — ❑ Primary
20 19.33 cfs - - -Inflow Arrea=Z 9a7 ac-
19 i — — — — — - — — — — — — — — — — — — — — — — — —
18 - - - - - - - - - -PeakElev=8-32.-3-6'16 — — — — — — — — - — — — — — — — — — — — — — —2,0"-
13 — —
31; - - - - - - - - - - - - - - q a.0�2
o 10
9 - - - - - - - -L-=269.0'-
5
4-
3-
2-
1
0
0 1 2
Time (hours)

PLI Storm Sewer& Dltch Calculations - 25 Yr Storm
Piedmont Ditches and Storm SeGaston County, NC 25-Year Duration=6 min, Inten=7.63 in/hr
Prepared by HDR, Inc Printed 8/27/2021
HydroCADO 10.10-5a s/n 05756 ©2020 HydroCAD Software Solutions LLC Page 31
Summary for Pond 5P: SB-5 (North)
Inflow Area = 2.907 ac, 89.85% Impervious, Inflow Depth = 0.71" for 25-Year event
Inflow = 19.50 cfs @ 0.12 hrs, Volume= 0.171 of
Outflow = 19.50 cfs @ 0.12 hrs, Volume= 0.171 af, Atten= 0%, Lag= 0.0 min
Primary = 19.50 cfs @ 0.12 hrs, Volume= 0.171 of
Routing by Stor-Ind method, Time Span= 0.00-2.00 hrs, dt= 0.01 hrs
Peak Elev= 838.10'@ 0.12 hrs
Device Routing Invert Outlet Devices
#1 Primary 835.44' 24.0" Round Culvert
L= 196.0' RCP, square edge headwall, Ke= 0.500
Inlet/ Outlet Invert= 835.44'/833.48' S= 0.0100 T Cc= 0.900
n= 0.012, Flow Area= 3.14 sf
Primary OutFlow Max=19.33 cfs @ 0.12 hrs HW=838.07' (Free Discharge)
L1=Culvert (Inlet Controls 19.33 cfs @ 6.15 fps)
Pond 5P: SB-5 (North)
Hydrograph
❑ Inflow
21 19s0.N ❑Primary
20 19.50ds Inflow Area=2.907 ac
19 i
,8 Peak Elev=838.10'
16
15 — — — — — - 24.0"
13 - - - Round Culvert
Iq
11 - - - - - n=0.012
0 10
LL 9 — — — — — — — L=196.0'
8
S=0.0100 T
5
4
3
2
1
0
0 1 2
Time (hours)

1
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 1
DA1- Stream Crossing at Road
Hydrograph type = SCS Runoff Peak discharge = 189.56 cfs
Storm frequency = 10 yrs Time to peak = 730 min
Time interval = 2 min Hyd. volume = 758,686 cuft
Drainage area = 74.730 ac Curve number = 78
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 28.10 min
Total precip. = 5.10 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA1- Stream Crossing at Road
Q (cfs) Hyd. No. 1 -- 10 Year Q (cfs)
210.00 210.00
180.00 180.00
150.00 150.00
120.00 120.00
90.00 90.00
60.00 60.00
30.00 30.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

2
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 2
DA2- Crossing at Road
Hydrograph type = SCS Runoff Peak discharge = 9.112 cfs
Storm frequency = 10 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 25,553 cuft
Drainage area = 2.500 ac Curve number = 79
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 14.70 min
Total precip. = 5.10 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA2- Crossing at Road
Q (cfs) Hyd. No. 2 -- 10 Year Q (cfs)
10.00 10.00
8.00 8.00
6.00 6.00
4.00 4.00
2.00 2.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

3
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 3
DA3- Crossing at Road
Hydrograph type = SCS Runoff Peak discharge = 22.57 cfs
Storm frequency = 10 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 58,525 cuft
Drainage area = 5.590 ac Curve number = 78
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 12.90 min
Total precip. = 5.10 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA3- Crossing at Road
Q (cfs) Hyd. No. 3-- 10 Year Q (cfs)
24.00 24.00
20.00 20.00
16.00 16.00
12.00 12.00
8.00 8.00
4.00 4.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3 Time (min)

4
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 4
DA4- Stream Crossing at Railroad
Hydrograph type = SCS Runoff Peak discharge = 354.47 cfs
Storm frequency = 10 yrs Time to peak = 730 min
Time interval = 2 min Hyd. volume = 1,423,773 cuft
Drainage area = 149.810 ac Curve number = 76
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 27.70 min
Total precip. = 5.10 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA4- Stream Crossing at Railroad
Q (cfs) Hyd. No. 4-- 10 Year Q (cfs)
400.00 400.00
350.00 350.00
300.00 300.00
250.00 250.00
200.00 200.00
150.00 150.00
100.00 100.00
50.00 50.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)

5
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 5
DA 5 - Railroad Crossing South
Hydrograph type = SCS Runoff Peak discharge = 51.83 cfs
Storm frequency = 10 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 145,344 cuft
Drainage area = 14.220 ac Curve number = 79
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 16.10 min
Total precip. = 5.10 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA 5 - Railroad Crossing South
Q (cfs) Hyd. No. 5-- 10 Year Q (cfs)
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 5 Time (min)

6
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 1
DA1- Stream Crossing at Road
Hydrograph type = SCS Runoff Peak discharge = 296.09 cfs
Storm frequency = 25 yrs Time to peak = 730 min
Time interval = 2 min Hyd. volume = 1,184,395 cuft
Drainage area = 74.730 ac Curve number = 78
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 28.10 min
Total precip. = 6.88 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA1- Stream Crossing at Road
Q (cfs) Hyd. No. 1 --25 Year Q (cfs)
320.00 320.00
280.00 280.00
240.00 240.00
200.00 200.00
160.00 160.00
120.00 120.00
80.00 80.00
40.00 40.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

7
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 2
DA2- Crossing at Road
Hydrograph type = SCS Runoff Peak discharge = 14.01 cfs
Storm frequency = 25 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 39,593 cuft
Drainage area = 2.500 ac Curve number = 79
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 14.70 min
Total precip. = 6.88 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA2- Crossing at Road
Q (cfs) Hyd. No. 2 --25 Year Q (cfs)
15.00 15.00
12.00 12.00
9.00 9.00
6.00 6.00
3.00 3.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

8
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 3
DA3- Crossing at Road
Hydrograph type = SCS Runoff Peak discharge = 34.99 cfs
Storm frequency = 25 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 91,364 cuft
Drainage area = 5.590 ac Curve number = 78
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 12.90 min
Total precip. = 6.88 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA3- Crossing at Road
Q (cfs) Hyd. No. 3--25 Year Q (cfs)
35.00 35.00
30.00 30.00
25.00 25.00
20.00 20.00
15.00 15.00
10.00 10.00
5.00 5.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3 Time (min)

9
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 4
DA4- Stream Crossing at Railroad
Hydrograph type = SCS Runoff Peak discharge = 564.89 cfs
Storm frequency = 25 yrs Time to peak = 730 min
Time interval = 2 min Hyd. volume = 2,257,193 cuft
Drainage area = 149.810 ac Curve number = 76
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 27.70 min
Total precip. = 6.88 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA4- Stream Crossing at Railroad
Q (cfs) Hyd. No. 4--25 Year Q (cfs)
640.00 640.00
560.00 560.00
480.00 480.00
400.00 400.00
320.00 320.00
240.00 240.00
160.00 160.00
80.00 80.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)

10
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 5
DA 5 - Railroad Crossing South
Hydrograph type = SCS Runoff Peak discharge = 79.66 cfs
Storm frequency = 25 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 225,203 cuft
Drainage area = 14.220 ac Curve number = 79
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 16.10 min
Total precip. = 6.88 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA 5 - Railroad Crossing South
Q (cfs) Hyd. No. 5--25 Year Q (cfs)
80.00 80.00
70.00 70.00
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 5 Time (min)

11
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 1
DA1- Stream Crossing at Road
Hydrograph type = SCS Runoff Peak discharge = 448.37 cfs
Storm frequency = 100 yrs Time to peak = 730 min
Time interval = 2 min Hyd. volume = 1,809,269 cuft
Drainage area = 74.730 ac Curve number = 78
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 28.10 min
Total precip. = 9.37 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA1- Stream Crossing at Road
Q (cfs) Hyd. No. 1 -- 100 Year Q (cfs)
480.00 480.00
420.00 420.00
360.00 360.00
300.00 300.00
240.00 240.00
180.00 180.00
120.00 120.00
60.00 60.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

12
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 2
DA2- Crossing at Road
Hydrograph type = SCS Runoff Peak discharge = 20.94 cfs
Storm frequency = 100 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 60,121 cuft
Drainage area = 2.500 ac Curve number = 79
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 14.70 min
Total precip. = 9.37 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA2- Crossing at Road
Q (cfs) Hyd. No. 2-- 100 Year Q (cfs)
21.00 21.00
18.00 18.00
15.00 1 1 1 1 115.00
12.00 12.00
9.00 9.00
6.00 6.00
3.00 3.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

13
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 3
DA3- Crossing at Road
Hydrograph type = SCS Runoff Peak discharge = 52.65 cfs
Storm frequency = 100 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 139,567 cuft
Drainage area = 5.590 ac Curve number = 78
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 12.90 min
Total precip. = 9.37 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA3- Crossing at Road
Q (cfs) Hyd. No. 3-- 100 Year Q (cfs)
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3 Time (min)

14
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 4
DA4- Stream Crossing at Railroad
Hydrograph type = SCS Runoff Peak discharge = 868.54 cfs
Storm frequency = 100 yrs Time to peak = 730 min
Time interval = 2 min Hyd. volume = 3,490,608 cuft
Drainage area = 149.810 ac Curve number = 76
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 27.70 min
Total precip. = 9.37 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA4- Stream Crossing at Railroad
Q (cfs) Hyd. No. 4-- 100 Year Q (cfs)
875.00 875.00
750.00 750.00
625.00 625.00
500.00 500.00
375.00 375.00
250.00 250.00
125.00 125.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)

15
Hydrograph Report
Hydraflow Hydrographs Extension for AutoCAD®Civil 3D®2018 by Autodesk, Inc.v2018.3 Tuesday, 12/7/2021
Hyd. No. 5
DA 5 - Railroad Crossing South
Hydrograph type = SCS Runoff Peak discharge = 119.11 cfs
Storm frequency = 100 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 341,967 cuft
Drainage area = 14.220 ac Curve number = 79
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 16.10 min
Total precip. = 9.37 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
DA 5 - Railroad Crossing South
Q (cfs) Hyd. No. 5-- 100 Year Q (cfs)
120.00 120.00
100.00 100.00
80.00 80.00
60.00 60.00
40.00 40.00
20.00 20.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 5 Time (min)

PLC Lithium Hydroxide Conversion Plant ���
Appendices
Appendix J — Stream and
Culvert Crossing Calculations

HY-8 Culvert Analysis Report

Culvert #C101
Crossing Discharge Data
Discharge Selection Method: Specify Minimum, Design, and Maximum Flow
Minimum Flow: 9.11 cfs
Design Flow: 14.01 cfs
Maximum Flow: 20.94 cfs

Table 1 - Summary of Culvert Flows at Crossing: Crossing 1 - DA2
Headwater Elevation Culvert 1 Discharge Roadway Discharge
(ft) Total Discharge(cfs) (cfs) (cfs) Iterations
889.96 9.11 9.11 0.00 1
890.09 10.29 10.29 0.00 1
890.22 11.48 11.48 0.00 1
890.35 12.66 12.66 0.00 1
890.50 14.01 14.01 0.00 1
890.62 15.03 15.03 0.00 1
890.76 16.21 16.21 0.00 1
890.92 17.39 17.39 0.00 1
891.08 18.57 18.57 0.00 1
891.26 19.76 19.76 0.00 1
891.45 20.94 20.94 0.00 1
893.02 28.80 28.80 0.00 Overtopping

Rating Curve Plot for Crossing: Crossing 1 - DA2
Total Rating Curve
Crossing:Crossing 1-DA2
893.5
893.D
8925
a
} 892.D
a�
w
aj 891.5
m
-Om 891.D
a)
T
890.5
890.D
10 15 20 25 30
Total Discharge(cfs)

Table 2 - Culvert Summary Table: Culvert 1
Total Culvert Headwat Inlet Outlet Normal Critical Outlet Tailwate Outlet Tailwate
Discharg Discharg er Control Control Flow Depth Depth Depth r Depth Velocity r
e(cfs) a(cfs) Elevatio Depth Depth Type (ft) (ft) (ft) (ft) (fus) Velocity
n ft ft ft fus
9.11 9.11 889.96 1.565 0.0* 1-S2n 0.563 1.077 0.592 0.308 11.693 2.740
10.29 10.29 890.09 1.692 0.0* 1-S2n 0.599 1.149 0.639 0.324 11.908 2.829
11.48 11.48 890.22 1.818 0.0* 1-S2n 0.634 1.216 0.672 0.340 12.390 2.911
12.66 12.66 890.35 1.946 0.0* 1-S2n 0.668 1.279 0.717 0.355 12.511 2.986
14.01 14.01 890.50 2.097 0.0* 5-S2n 0.704 1.348 0.755 0.371 12.901 3.066
15.03 15.03 890.62 2.216 0.0* 5-S2n 0.731 1.397 0.790 0.382 13.025 3.122
16.21 16.21 890.76 2.362 0.0* 5-S2n 0.762 1.451 0.827 0.395 13.215 3.184
17.39 17.39 890.92 2.517 0.0* 5-S2n 0.791 1.503 0.859 0.407 13.483 3.243
18.57 18.57 891.08 2.683 0.0* 5-S2n 0.821 1.551 0.895 0.419 13.635 3.298
19.76 1 19.76 1 891.26 1 2.860 1 0.134 1 5-S2n 1 0.849 1 1.597 1 0.932 1 0.430 1 13.778 3.351
20.94 1 20.94 1 891.45 1 3.049 1 0.321 1 5-S2n 1 0.877 1 1.639 1 0.965 1 0.441 1 13.947 3.402

* Full Flow Headwater elevation is below inlet invert.
Straight Culvert
Inlet Elevation(invert):888.40 ft, Outlet Elevation(invert):885.39 ft
Culvert Length:65.60 ft, Culvert Slope:0.0459

Culvert Performance Curve Plot: Culvert 1
Performance Curve
culven:cUIVffI r
0 0
Inlet Control Elev bullet Control Elev
893
892
0
a
a)
w 891
2
m -�
890
m
a)
_
889
Y
10 15 20 25 30
Total Discharge Scfs)

Water Surface Profile Plot for Culvert: Culvert 1 Culvert #C101
Crossuig- Crossuig 1 -DA2,Desigxi Discharge - 14.0 cfs
Cuh-ert-Cuh ert 1-Cuh-en Discharge-14-6 cfs
894
893
892
U 891
c �
0 890
m _
w 889
888
887
886
885
-20 0 20 40 60 80
statiar{ft)
S
Inlet 5tatlon: U.UU tt
Inlet Elevation: 888.40 ft
Outlet Station: 65.53 ft
Outlet Elevation: 885.39 ft
Number of Barrels: 1
Culvert Data Summary - Culvert 1
Barrel Shape: Circular
Barrel Diameter: 2.00 ft
Barrel Material: Concrete
Embedment: 0.00 in
Barrel Manning's n: 0.0120
Culvert Type: Straight
Inlet Configuration: Square Edge with Headwall
Inlet Depression: None

Table 3 - Downstream Channel Rating Curve (Crossing: Crossing 1 - DA2)
Flow(cfs) Water Surface Depth (ft) Velocity(ft/s) Shear(psf) Froude Number
Elev (ft)
9.11 885.70 0.31 2.74 0.77 1.13
10.29 885.71 0.32 2.83 0.81 1.14
11.48 885.73 0.34 2.91 0.85 1.14
12.66 885.75 0.36 2.99 0.89 1.15
14.01 885.76 0.37 3.07 0.93 1.16
15.03 885.77 0.38 3.12 0.95 1.16
16.21 885.79 0.40 3.18 0.99 1.17
17.39 885.80 0.41 3.24 1.02 1.18
18.57 885.81 0.42 3.30 1.05 1.18
19.76 885.82 0.43 3.35 1.07 1.19
20.94 885.83 0.44 3.40 1.10 1.19
Tailwater Channel Data - Crossing 1 - DA2
Tailwater Channel Option: Irregular Channel
Channel Slope: 0.0400
User Defined Channel Cross-Section:
Coord No. Station (ft) Elevation (ft) Manning's n
1 0.00 888.26 0.0350
2 16.95 886.56 0.0350
3 35.27 885.43 0.0350
4 39.94 885.39 0.0350
5 70.19 886.41 0.0350
6 93.78 886.85 0.0000
Roadway Data for Crossing: Crossing 1 - DA2
Roadway Profile Shape: Irregular Roadway Shape (coordinates)
Irregular Roadway Cross-Section:
Coord No. Station (ft) Elevation (ft)
0 350.00 894.44
1 363.74 893.99
2 400.00 893.02
Roadway Surface: Paved
Roadway Top Width: 26.00 ft

Culvert #C102
Crossing Discharge Data
Discharge Selection Method: Specify Minimum, Design, and Maximum Flow
Minimum Flow: 22.57 cfs
Design Flow: 34.99 cfs
Maximum Flow: 52.65 cfs

Table 4 - Summary of Culvert Flows at Crossing: Crossing 2 - DA3
Headwater Elevation Culvert 2 Discharge Roadway Discharge
(ft) Total Discharge(cfs) (cfs) (cfs) Iterations
873.46 22.57 22.57 0.00 1
873.64 25.58 25.58 0.00 1
873.82 28.59 28.59 0.00 1
873.99 31.59 31.59 0.00 1
874.19 34.99 34.99 0.00 1
874.35 37.61 37.61 0.00 1
874.54 40.62 40.62 0.00 1
874.74 43.63 43.63 0.00 1
874.95 46.63 46.63 0.00 1
875.17 49.64 49.64 0.00 1
875.41 52.65 52.65 0.00 1
878.21 79.45 79.45 0.00 Overtopping

Rating Curve Plot for Crossing: Crossing 2 - DA3
Total Rating Curve
Crossing:Crossing 2-DA3
879
878
a 877
6
}
a)
w 876
a�
m 875
aD
T
87d
20 30 40 b0 60 70 80 90
Total Discharge(cfs)

Table 5 - Culvert Summary Table: Culvert 2
Total Culvert Headwat Inlet Outlet Normal Critical Outlet Tailwate Outlet Tailwate
Discharg Discharg er Control Control Flow Depth Depth Depth r Depth Velocity r
e(cfs) a(cfs) Elevatio Depth Depth Type (ft) (ft) (ft) (ft) (fus) Velocity
n ft ft ft fus
22.57 22.57 873.46 2.173 0.0* 1-S2n 0.720 1.529 0.835 0.288 14.048 2.690
25.58 25.58 873.64 2.353 0.0* 1-S2n 0.768 1.632 0.901 0.305 14.308 2.786
28.59 28.59 873.82 2.529 0.0* 1-S2n 0.812 1.730 0.964 0.320 14.577 2.874
31.59 31.59 873.99 2.703 0.0* 1-S2n 0.855 1.823 1.022 0.335 14.870 2.955
34.99 34.99 874.19 2.903 0.0* 1-S2n 0.901 1.922 1.089 0.350 15.094 3.039
37.61 37.61 874.35 3.062 0.027 5-S2n 0.935 1.995 1.138 0.362 15.293 3.100
40.62 40.62 874.54 3.251 0.237 5-S2n 0.973 2.075 1.194 0.374 15.485 3.166
43.63 43.63 874.74 3.450 0.454 5-S2n 1.011 2.152 1.247 0.386 15.699 3.228
46.63 46.63 874.95 3.660 0.676 5-S2n 1.047 2.224 1.301 0.397 15.870 3.292
49.64 1 49.64 1 875.17 1 3.883 1 1.259 1 5-S2n 1 1.083 1 2.293 1 1.351 1 0.408 1 16.067 3.356
52.65 1 52.65 1 875.41 1 4.120 1 1.462 1 5-S2n 1 1.117 1 2.358 1 1.402 1 0.418 1 16.248 3.417

* Full Flow Headwater elevation is below inlet invert.
Straight Culvert
Inlet Elevation(invert):871.29 ft, Outlet Elevation(invert):868.54 ft
Culvert Length:45.49 ft, Culvert Slope:0.0606

Culvert Performance Curve Plot: Culvert 2
Performance Curve
Culver:aulvfft z
0 0
Inlet Control Elev bullet Control Elev
879
878
0
877
a
m 876
}
w 875 --�
874 CU
—
41 873 Ar--
872 r s
- r r
871
20 30 40 b0 60 70 80 90
Total Discharge(cfs)

Culvert #C102
Water Surface Profile Plot for Culvert: Culvert 2
Crossuig- Crossuig 2 -DA3,Desigxi Discharge - 35.0 cfs
Cuh•ert-Cuhert 2,Cuh•en Discharge-35.0 cfs
880
878
—876
C
0
874 ---
a}i
w -
872
870
868
-10 0 10 20 30 40 50 60
Station(ft)
S
Inlet 5tatlon: U.UU tt
Inlet Elevation: 871.29 ft
Outlet Station: 45.41 ft
Outlet Elevation: 868.54 ft
Number of Barrels: 1
Culvert Data Summary - Culvert 2
Barrel Shape: Circular
Barrel Diameter: 3.00 ft
Barrel Material: Concrete
Embedment: 0.00 in
Barrel Manning's n: 0.0120
Culvert Type: Straight
Inlet Configuration: Square Edge with Headwall
Inlet Depression: None

Table 6 - Downstream Channel Rating Curve (Crossing: Crossing 2 - DA3)
Flow(cfs) Water Surface Depth (ft) Velocity(ft/s) Shear(psf) Froude Number
Elev (ft)
22.57 868.83 0.29 2.69 0.72 1.12
25.58 868.84 0.30 2.79 0.76 1.13
28.59 868.86 0.32 2.87 0.80 1.14
31.59 868.87 0.33 2.95 0.84 1.15
34.99 868.89 0.35 3.04 0.87 1.16
37.61 868.90 0.36 3.10 0.90 1.16
40.62 868.91 0.37 3.17 0.93 1.17
43.63 868.93 0.39 3.23 0.96 1.17
46.63 868.94 0.40 3.29 0.99 1.18
49.64 868.95 0.41 3.36 1.02 1.19
52.65 868.96 0.42 3.42 1.04 1.19
Tailwater Channel Data - Crossing 2 - DA3
Tailwater Channel Option: Irregular Channel
Channel Slope: 0.0400
User Defined Channel Cross-Section:
Coord No. Station (ft) Elevation (ft) Manning's n
1 0.00 870.14 0.0350
2 26.21 868.93 0.0350
3 45.28 868.54 0.0350
4 58.05 868.57 0.0350
5 71.82 868.72 0.0350
6 93.78 869.09 0.0000
Roadway Data for Crossing: Crossing 2 - DA3
Roadway Profile Shape: Irregular Roadway Shape (coordinates)
Irregular Roadway Cross-Section:
Coord No. Station (ft) Elevation (ft)
0 950.00 879.78
1 990.06 878.53
2 1000.00 878.21
Roadway Surface: Paved
Roadway Top Width: 26.00 ft

Stream Crossing No. 3
Crossing Discharge Data
Discharge Selection Method: Specify Minimum, Design, and Maximum Flow
Minimum Flow: 189.56 cfs
Design Flow: 296.09 cfs
Maximum Flow: 448.37 cfs

Table 7 - Summary of Culvert Flows at Crossing: Crossing 3 - DA1
Headwater Elevation Open Bottom Arch 3 Roadway Discharge
(ft) Total Discharge(cfs) Discharge(cfs) (cfs) Iterations
832.11 189.56 189.56 0.00 1
832.54 215.44 215.44 0.00 1
832.97 241.32 241.32 0.00 1
833.40 267.20 267.20 0.00 1
833.88 296.09 296.09 0.00 1
834.27 318.97 318.97 0.00 1
834.71 344.85 344.85 0.00 1
835.15 370.73 370.73 0.00 1
835.69 396.61 396.61 0.00 1
836.29 422.49 422.49 0.00 1
836.89 448.37 448.37 0.00 1
839.48 540.51 540.51 0.00 Overtopping

Rating Curve Plot for Crossing: Crossing 3 - DA1
Total Rating Curve
Crossing:Crossing 3-DAt
84fl
839
838
0
a
837
}
a)
w 83g
a�
835
ca
m
= 834
833
832
200 300 400 500 500
Tatal Discharge�cfs)

Table 8 - Culvert Summary Table: Open Bottom Arch 3
Total Culvert Headwat Inlet Outlet Normal Critical Outlet Tailwate Outlet Tailwate
Discharg Discharg er Control Control Flow Depth Depth Depth r Depth Velocity r
e(cfs) a(cfs) Elevatio Depth Depth Type (ft) (ft) (ft) (ft) (fus) Velocity
n ft ft ft fus
189.56 189.56 832.11 4.141 0.0* 1-S2n 1.951 2.227 1.951 2.363 9.907 8.932
215.44 215.44 832.54 4.570 0.241 1-S2n 2.142 2.423 2.142 2.528 10.304 9.250
241.32 241.32 832.97 4.998 0.825 1-S2n 2.331 2.613 2.336 2.683 10.638 9.540
267.20 267.20 833.40 5.426 1.448 5-S2n 2.520 2.791 2.520 2.829 10.982 9.806
296.09 296.09 833.88 5.909 2.192 5-S2n 2.732 2.981 2.732 2.983 11.303 10.079
318.97 318.97 834.27 6.300 2.846 5-S2n 2.906 3.126 2.906 3.100 11.522 10.282
344.85 344.85 834.71 6.742 3.630 5-S2n 3.108 3.287 3.108 3.226 11.745 10.497
370.73 370.73 835.15 7.184 4.457 5-S2n 3.317 3.443 3.317 3.347 11.946 10.700
396.61 396.61 835.69 7.720 5.318 5-S2n 3.540 3.584 3.540 3.463 12.109 10.892
422.49 422.49 836.29 8.319 8.203 7-M2 3.787 3.722 3.722 3.575 12.394 11.074
c
448.37 448.37 836.89 8.918 8.541 7-M2 4.062 3.855 3.855 3.683 12.801 11.248
c

* Full Flow Headwater elevation is below inlet invert.
Straight Culvert
Inlet Elevation(invert):827.97 ft, Outlet Elevation(invert):824.00 ft
Culvert Length:111.46 ft, Culvert Slope:0.0356

Culvert Performance Curve Plot: Open Bottom Arch 3
Performance Curve
Culvert:Open Bottom Arch 3
0 0
Inlet Control Elev bullet Control Elev
840
838
v
836
m
m
w 834 CU
J'
01 l
832
m
= 830
X
x
828
260 300 400 500 500
Tatal Discharge�cfs)

Stream Crossing No. 3
Water Surface Profile Plot for Culvert: Open Bottom Arch 3
Crossing- Crossing 3 -DAL Desigxi Discharge- 296.1 cfs
C&ert Open Bottom Arch 3,Cuhert Discharge-296.1 cfs
842
840
838
836
834 ---
0
} 832
m
w 830
828 �-
826
824
0 50 100
Station(ft)
S
Inlet 5tatlon: U.UU tt
Inlet Elevation: 827.97 ft
Outlet Station: 111.39 ft
Outlet Elevation: 824.00 ft
Number of Barrels: 1
Culvert Data Summary - Open Bottom Arch 3
Barrel Shape: Arch, Open Bottom
Barrel Span: 10.00 ft
Barrel Rise: 5.25 ft
Barrel Material: Corrugated Steel
Embedment: 0.00 in
Barrel Manning's n: 0.0350 (top and sides)
Manning's n: 0.0350 (bottom)
Culvert Type: Straight
Inlet Configuration: Thin Edge Projecting
Inlet Depression: None

Table 9 - Downstream Channel Rating Curve (Crossing: Crossing 3 - DA1)
Flow(cfs) Water Surface Depth (ft) Velocity(ft/s) Shear(psf) Froude Number
Elev(ft)
189.56 826.36 2.36 8.93 3.69 1.20
215.44 826.53 2.53 9.25 3.94 1.21
241.32 826.68 2.68 9.54 4.19 1.21
267.20 826.83 2.83 9.81 4.41 1.22
296.09 826.98 2.98 10.08 4.65 1.23
318.97 827.10 3.10 10.28 4.84 1.23
344.85 827.23 3.23 10.50 5.03 1.24
370.73 827.35 3.35 10.70 5.22 1.24
396.61 827.46 3.46 10.89 5.40 1.25
422.49 827.57 3.57 11.07 5.58 1.25
448.37 827.68 3.68 11.25 5.75 1.25
Tailwater Channel Data - Crossing 3 - DA1
Tailwater Channel Option: Irregular Channel
Channel Slope: 0.0250
User Defined Channel Cross-Section:
Coord No. Station (ft) Elevation (ft) Manning's n
1 0.00 835.17 0.0350
2 25.14 830.00 0.0350
3 47.91 828.00 0.0350
4 54.56 824.00 0.0350
5 60.25 824.00 0.0350
6 64.95 828.18 0.0350
7 76.03 830.91 0.0350
8 99.59 834.74 0.0000
Roadway Data for Crossing: Crossing 3 - DA1
Roadway Profile Shape: Irregular Roadway Shape (coordinates)
Irregular Roadway Cross-Section:
Coord No. Station (ft) Elevation (ft)
0 2000.00 841.16
1 2050.00 840.07
2 2083.00 839.64
3 2150.00 839.48
4 2200.00 839.91
Roadway Surface: Paved
Roadway Top Width: 26.00 ft

Stream Crossing No. 4
Crossing Discharge Data
Discharge Selection Method: Specify Minimum, Design, and Maximum Flow
Minimum Flow: 354.47 cfs
Design Flow: 564.89 cfs
Maximum Flow: 868.54 cfs

Table 10 - Summary of Culvert Flows at Crossing: Railroad Crossing 4 - DA4
Headwater Elevation Open Bottom Arch 4- Roadway Discharge
(ft) Total Discharge(cfs) Railroad Discharge (cfs) Iterations
cfs
821.09 354.47 354.47 0.00 1
821.66 405.88 405.88 0.00 1
822.20 457.28 457.28 0.00 1
822.72 508.69 508.69 0.00 1
823.29 564.89 564.89 0.00 1
823.76 611.51 611.51 0.00 1
824.28 662.91 662.91 0.00 1
824.82 714.32 714.32 0.00 1
825.35 765.73 765.73 0.00 1
825.89 817.13 817.13 0.00 1
826.45 868.54 868.54 0.00 1
838.23 1517.23 1517.23 0.00 Overtopping

Rating Curve Plot for Crossing: Railroad Crossing 4 - DA4
Total Rating Curve
Crossing:Railroad Crossing 4-DA4
838
83S
v 834
0
a
m 832
}
a)
w 830
a�
828
ai 826
824
822
400 500 800 1000 1200 1400 1600
Total Discharge Scfs)

Table 11 - Culvert Summary Table: Open Bottom Arch 4 - Railroad
Total Culvert Headwat Inlet Outlet Normal Critical Outlet Tailwate Outlet Tailwate
Discharg Discharg er Control Control Flow Depth Depth Depth r Depth Velocity r
e(cfs) a(cfs) Elevatio Depth Depth Type (ft) (ft) (ft) (ft) (fus) Velocity
n ft (ft) (ft fus
354.47 354.47 821.09 4.836 0.0* 1 tS1 1.916 2.708 5.105 5.105 5.426 7.682
405.88 405.88 821.66 5.407 0.0* 1 tS1 2.094 2.960 5.420 5.420 5.934 7.944
457.28 457.28 822.20 5.951 0.0* 1-S2n 2.266 3.202 2.273 5.712 14.591 8.183
508.69 508.69 822.72 6.469 0.004 1-S2n 2.432 3.437 2.432 5.985 15.204 8.402
564.89 564.89 823.29 7.036 0.799 1-S2n 2.610 3.685 2.610 6.264 15.774 8.623
611.51 611.51 823.76 7.506 1.497 5-S2n 2.755 3.876 2.755 6.483 16.215 8.794
662.91 662.91 824.28 8.030 2.281 5-S2n 2.914 4.083 2.914 6.713 16.672 8.972
714.32 714.32 824.82 8.566 3.095 5-S2n 3.070 4.284 3.070 6.932 17.101 9.139
765.73 765.73 825.35 9.102 3.941 5-S2n 3.226 4.481 3.232 7.141 17.473 9.298
817.13 817.13 825.89 9.638 4.808 5-S2n 3.380 4.673 3.404 7.342 17.772 9.449
868.54 868.54 826.45 10.196 5.719 5-S2n 3.534 4.849 3.534 7.536 18.251 9.592

* Full Flow Headwater elevation is below inlet invert.
Straight Culvert
Inlet Elevation(invert):816.25 ft, Outlet Elevation(invert):808.00 ft
Culvert Length:162.06 ft, Culvert Slope:0.0510

Culvert Performance Curve Plot: Open Bottom Arch 4 - Railroad
Performance Curve
Culvert:Open Bottom Arch 4-Railroad
0 0
840 Inlet Control Elev bullet Control Elev
_ 835
v
0
o �
} 830 .'
a)
w
m 825 �
CU
rr
r
= 820 r
r
400 500 800 1000 1200 1400 1600
Total Discharge Scfs)

Stream Crossing No. 4
Water Surface Profile Plot for Culvert: Open Bottom Arch 4 - Railroad
Crossing-Railroad Crossing 4-DAa.Dcstgn Discharge-564.9 cfs
Culvert-Open Bottom Arch 4-Railroad-Cuh•ert Discharge-564.4 cf
840
835
830
c
0 825
a}i
w 820
815 ---
810
-50 0 50 100 150 200
Station(ft)
S
Inlet 5tatlon: U.UU tt
Inlet Elevation: 816.25 ft
Outlet Station: 161.85 ft
Outlet Elevation: 808.00 ft
Number of Barrels: 1
Culvert Data Summary - Open Bottom Arch 4 - Railroad
Barrel Shape: Arch, Open Bottom
Barrel Span: 14.00 ft
Barrel Rise: 7.25 ft
Barrel Material: Corrugated Aluminum
Embedment: 0.00 in
Barrel Manning's n: 0.0240 (top and sides)
Manning's n: 0.0350 (bottom)
Culvert Type: Straight
Inlet Configuration: Thin Edge Projecting
Inlet Depression: None

Table 12 - Downstream Channel Rating Curve (Crossing: Railroad Crossing 4 - DA4)
Flow(cfs) Water Surface Depth (ft) Velocity(ft/s) Shear(psf) Froude Number
Elev (ft)
354.47 813.10 5.10 7.68 3.19 0.78
405.88 813.42 5.42 7.94 3.38 0.78
457.28 813.71 5.71 8.18 3.56 0.79
508.69 813.98 5.98 8.40 3.73 0.79
564.89 814.26 6.26 8.62 3.91 0.80
611.51 814.48 6.48 8.79 4.05 0.80
662.91 814.71 6.71 8.97 4.19 0.81
714.32 814.93 6.93 9.14 4.33 0.81
765.73 815.14 7.14 9.30 4.46 0.81
817.13 815.34 7.34 9.45 4.58 0.82
868.54 815.54 7.54 9.59 4.70 0.82
Tailwater Channel Data - Railroad Crossing 4 - DA4
Tailwater Channel Option: Irregular Channel
Channel Slope: 0.0100
User Defined Channel Cross-Section:
Coord No. Station (ft) Elevation (ft) Manning's n
1 0.00 816.00 0.0350
2 15.50 816.00 0.0350
3 26.56 808.00 0.0350
4 29.35 808.00 0.0350
5 42.14 820.00 0.0350
6 52.13 821.38 0.0350
Roadway Data for Crossing: Railroad Crossing 4 - DA4
Roadway Profile Shape: Irregular Roadway Shape (coordinates)
Irregular Roadway Cross-Section:
Coord No. Station (ft) Elevation (ft)
0 1975.00 840.76
1 2083.00 838.23
2 2175.00 838.46
3 2425.00 840.96
Roadway Surface: Paved
Roadway Top Width: 45.00 ft

Culvert #C103
Crossing Discharge Data
Discharge Selection Method: Specify Minimum, Design, and Maximum Flow
Minimum Flow: 51.83 cfs
Design Flow: 79.66 cfs
Maximum Flow: 119.11 cfs

Table 13 - Summary of Culvert Flows at Crossing: Crossing 5 - DA 5
Headwater Elevation Culvert 5 Discharge Roadway Discharge
(ft) Total Discharge(cfs) (cfs) (cfs) Iterations
883.13 51.83 51.83 0.00 1
883.38 58.56 58.56 0.00 1
883.64 65.29 65.29 0.00 1
883.89 72.01 72.01 0.00 1
884.20 79.66 79.66 0.00 1
884.44 85.47 85.47 0.00 1
884.73 92.20 92.20 0.00 1
885.05 98.93 98.93 0.00 1
885.38 105.65 105.65 0.00 1
885.74 112.38 112.38 0.00 1
886.12 119.11 119.11 0.00 1
894.00 202.93 202.93 0.00 Overtopping

Rating Curve Plot for Crossing: Crossing 5 - DA 5
Total Rating Curve
Crossing:Crossing 5-DA 5
893
892
891
0 890
CU
a}i 889
w 888
a�
887
ID, 886
885
004
883
60 80 100 120 140 160 180 200 220
Total Discharge(cfs)

Table 14 - Culvert Summary Table: Culvert 5
Total Culvert Headwat Inlet Outlet Normal Critical Outlet Tailwate Outlet Tailwate
Discharg Discharg er Control Control Flow Depth Depth Depth r Depth Velocity r
e(cfs) a(cfs) Elevatio Depth Depth Type (ft) (ft) (ft) (ft) (fus) Velocity
n ft ft ft fus
51.83 51.83 883.13 3.178 0.0* 1-S2n 1.215 2.162 1.324 0.513 14.275 4.408
58.56 58.56 883.38 3.433 0.002 1-S2n 1.295 2.304 1.422 0.535 14.623 4.594
65.29 65.29 883.64 3.687 0.296 1-S2n 1.371 2.439 1.517 0.556 14.942 4.766
72.01 72.01 883.89 3.944 0.601 1-S2n 1.445 2.566 1.607 0.577 15.251 4.924
79.66 79.66 884.20 4.248 0.961 5-S2n 1.525 2.703 1.707 0.599 15.577 5.092
85.47 85.47 884.44 4.489 1.243 5-S2n 1.584 2.802 1.783 0.615 15.783 5.212
92.20 92.20 884.73 4.784 1.582 5-S2n 1.652 2.911 1.865 0.633 16.047 5.343
98.93 98.93 885.05 5.098 2.425 5-S2n 1.717 3.014 1.949 0.650 16.273 5.467
105.65 105.65 885.38 5.433 2.737 5-S2n 1.782 3.111 2.030 0.667 16.503 5.584
112.381 112.38 1 885.74 1 5.791 1 3.064 1 5-S2n 1 1.846 1 3.202 1 2.108 1 0.683 1 16.736 1 5.697
119.111 119.11 1 886.12 1 6.173 1 3.405 1 5-S2n 1 1.908 1 3.287 1 2.185 1 0.699 1 16.959 1 5.804

* Full Flow Headwater elevation is below inlet invert.
Straight Culvert
Inlet Elevation(invert):879.95 ft, Outlet Elevation(invert):876.99 ft
Culvert Length:108.04 ft, Culvert Slope:0.0274

Culvert Performance Curve Plot: Culvert 5
Performance Curve
cUtven:aUIVfft s
0 0
894 Inlet Control Elev bullet Control Elev
892
890
a
}
a) 888
w
a5 886
� rrr
= 882 X
000 rrr
60 80 100 120 140 160 180 200 220
Tatal Discharge(cfs)

Culvert #C103
Water Surface Profile Plot for Culvert: Culvert 5
Crossing- Crossing 5 -DA 5,Design Discharge- 79.7 cfs
Culvert-Culvert 5,Culvert Discharge-79.7 cfs
892
890
888
v 886
884 ---
}
w 882
880
878
876 ___
874
-20 0 20 40 60 80 100 120 140
station(ft)
S
Inlet Station: U.UU tt
Inlet Elevation: 879.95 ft
Outlet Station: 108.00 ft
Outlet Elevation: 876.99 ft
Number of Barrels: 1
Culvert Data Summary - Culvert 5
Barrel Shape: Circular
Barrel Diameter: 4.00 ft
Barrel Material: Concrete
Embedment: 0.00 in
Barrel Manning's n: 0.0120
Culvert Type: Straight
Inlet Configuration: Square Edge with Headwall
Inlet Depression: None

Table 15 - Downstream Channel Rating Curve (Crossing: Crossing 5 - DA 5)
Flow(cfs) Water Surface Depth (ft) Velocity(ft/s) Shear(psf) Froude Number
Elev (ft)
51.83 875.41 0.51 4.41 1.98 1.50
58.56 875.44 0.54 4.59 2.07 1.51
65.29 875.46 0.56 4.77 2.15 1.53
72.01 875.48 0.58 4.92 2.23 1.54
79.66 875.50 0.60 5.09 2.32 1.55
85.47 875.51 0.61 5.21 2.38 1.56
92.20 875.53 0.63 5.34 2.45 1.57
98.93 875.55 0.65 5.47 2.51 1.58
105.65 875.57 0.67 5.58 2.58 1.59
112.38 875.58 0.68 5.70 2.64 1.60
119.11 875.60 0.70 5.80 2.70 1.60
Tailwater Channel Data - Crossing 5 - DA 5
Tailwater Channel Option: Irregular Channel
Channel Slope: 0.0620
User Defined Channel Cross-Section:
Coord No. Station (ft) Elevation (ft) Manning's n
1 0.00 876.00 0.0350
2 15.40 875.30 0.0350
3 32.40 874.90 0.0350
4 56.40 875.40 0.0350
5 69.30 876.30 0.0350
6 80.00 877.00 0.0350
Roadway Data for Crossing: Crossing 5 - DA 5
Roadway Profile Shape: Irregular Roadway Shape (coordinates)
Irregular Roadway Cross-Section:
Coord No. Station (ft) Elevation (ft)
0 0.00 893.00
1 96.00 894.00
2 197.00 895.00
Roadway Surface: Paved
Roadway Top Width: 50.00 ft

PLC I Lithium Hydroxide Conversion Plant ���
Appendices
Appendix K — Outlet
Protection Calculations

PROTECTIONOUTLET
HydroxideLithium .
D- --• NO.: 1 1
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PLC I Lithium Hydroxide Conversion Plant ���
Appendices
FN
440 South Church Street555 Fayetteville Street,
Suite 900
Charlotte, NC 27601-3034
919.232.6600
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